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Appendix P CMF Gap Analysis P-1
Table of Contents 1. Introduction ........................................................................................................................................ P-5 2. Access Management .......................................................................................................................... P-6 2.1 Existing CMFs in the CMF Clearinghouse .................................................................................. P-6 2.2 Active/Recent Research Projects ................................................................................................. P-7 3. Advanced Technology and Intelligent Transportation Systems ...................................................... P-10 3.1 Existing CMFs in the CMF Clearinghouse ................................................................................ P-10 3.2 Active/Recent Research Projects................................................................................................ P-10 4. Highway Alignment ......................................................................................................................... P-12 4.1 Existing CMFs in the CMF Clearinghouse ................................................................................ P-12 4.2 Active/Recent Research projects................................................................................................ P-12 5. Bicyclists and Pedestrians ................................................................................................................ P-14 5.1 Existing CMFs in the CMF Clearinghouse ................................................................................ P-14 5.2 Active/Recent Research Projects................................................................................................ P-14 6. Highway Delineation ....................................................................................................................... P-18 6.1 Existing CMFs in the CMF Clearinghouse ................................................................................ P-18 6.2 Active/Recent Research Projects ............................................................................................... P-18 7. Highway Lighting ............................................................................................................................ P-21 7.1 Existing CMFs in the CMF Clearinghouse ................................................................................ P-21 7.2 Active/Recent Research Projects ............................................................................................... P-21 8. Interchanges/Ramps ......................................................................................................................... P-23 8.1 Existing CMFs in the CMF Clearinghouse ................................................................................ P-23 8.2 Active/Recent Research Projects ............................................................................................... P-23 9. Intersection Geometry ...................................................................................................................... P-25 9.1 Existing CMFs in the CMF Clearinghouse ................................................................................ P-25 9.2 Active/Recent Research Projects ............................................................................................... P-25 10. Intersection Traffic Control ........................................................................................................... P-30 10.1 Existing CMFs in the CMF Clearinghouse .............................................................................. P-30 10.2 Active/Recent Research Projects ............................................................................................. P-30 11. Pavement Treatment and Resurfacing ........................................................................................... P-34 11.1 Existing CMFs in the CMF Clearinghouse .............................................................................. P-34 11.2 Active Research Projects.......................................................................................................... P-34 12. Roadside ......................................................................................................................................... P-36 12.1 Existing CMFs in the CMF Clearinghouse .............................................................................. P-36 P-2
12.2 Active/Recent Research Projects ............................................................................................. P-36 13. Roadway ........................................................................................................................................ P-39 13.1 Existing CMFs in the CMF Clearinghouse .............................................................................. P-39 13.2 Active/Recent Research Projects ............................................................................................. P-39 14. Railroad Crossing ........................................................................................................................... P-42 14.1 Existing CMFs in the CMF Clearinghouse .............................................................................. P-42 14.2 Active/Recent Research Projects ............................................................................................. P-42 15. Highway Shoulders ........................................................................................................................ P-44 15.1 Existing CMFs in the CMF Clearinghouse .............................................................................. P-44 15.2 Active/Recent Research Projects ............................................................................................. P-44 16. Highway Signs ............................................................................................................................... P-46 16.1 Existing CMFs in the CMF Clearinghouse .............................................................................. P-46 16.2 Active/Recent Research Projects ............................................................................................. P-46 17. Bridges and Structures ................................................................................................................... P-49 17.1 Existing CMFs in the CMF Clearinghouse .............................................................................. P-49 17.2 Active/Recent Research Projects ............................................................................................. P-49 18. Highway Work Zones .................................................................................................................... P-51 18.1 Existing CMFs in the CMF Clearinghouse .............................................................................. P-51 18.2 Active/Recent Research Projects ............................................................................................. P-51 19. Other Countermeasures .................................................................................................................. P-53 19.1 Existing CMFs in the CMF Clearinghouse .............................................................................. P-53 19.2 Active/Recent Research Projects ............................................................................................. P-53 Table 1. CMFs of Interest for Access Management .................................................................................. P-8 Table 2. CMFs of Interest for Advanced Technology and Intelligent Transportation Systems .............. P-11 Table 3. CMFs of Interest for Alignments ............................................................................................... P-13 Table 4. CMFs of Interest for Bicyclists and Pedestrians ........................................................................ P-15 Table 5. CMFs of Interest for Delineation ............................................................................................... P-19 Table 6. CMFs of Interest for Lighting .................................................................................................... P-22 Table 7. CMFs of Interest for Interchanges ............................................................................................. P-24 Table 8. CMFs of Interest for Intersection Geometry .............................................................................. P-26 Table 9. CMFs of Interest for Intersection Traffic Control ..................................................................... P-31 Table 10. CMFs of Interest for Pavement Treatment and Resurfacing ................................................... P-35 Table 11. CMFs of Interest for Roadside ................................................................................................. P-37 P-3
Table 12. CMFs of Interest for Roadway ................................................................................................ P-40 Table 13. CMFs of Interest for Railroad Crossing................................................................................... P-43 Table 14. CMFs of Interest for Shoulders................................................................................................ P-45 Table 15. CMFs of Interest for Signs ....................................................................................................... P-47 Table 16. CMFs of Interest for Bridges and Structures ........................................................................... P-50 Table 17. CMFs of Interest for Work Zone ............................................................................................. P-52 Table 18. CMFs of Interest for Other Countermeasures .......................................................................... P-54 P-4
1. INTRODUCTION This Appendix provides a summary of key findings from Task 9 â Gap Analysis. After identifying and reviewing all existing Crash Modification Factors and Crash Modification Functions (referred to hereafter as CMFs) in the CMF Clearinghouse under Task 7 of this project, the research team developed the following list of 18 countermeasure categories: 1) Access Management 2) Advanced Technology and Intelligent Transportation Systems 3) Highway Alignment 4) Bicyclists and Pedestrians 5) Highway Delineation 6) Highway Lighting 7) Interchanges/Ramps 8) Intersection Geometry 9) Intersection Traffic Control 10) Pavement Treatment and Resurfacing 11) Roadside 12) Roadway 13) Railroad Crossing 14) Highway Shoulders 15) Highway Signs 16) Bridges and Structures 17) Highway Work Zones 18) Others These categories, and a list of CMFs of interest within each, were adapted with minor revisions from a list first developed by as part of FHWAâs Countermeasure Service Life Guide (Report FHWA-SA-21- 026). Under this FHWA study, the team collected and consolidated information from both the CMF Clearinghouse and State DOT sources to develop the list of countermeasures. The team first started with reviewing the countermeasure name, countermeasure category and subcategory of all CMFs from the CMF Clearinghouse and then supplemented that with information from 15 States that included countermeasure lists, Highway Safety Improvement Program (HSIP) manuals, HSIP reports, and implementation tools. Most State lists included several countermeasures that are not in the CMF Clearinghouse list. In these cases, the team added the countermeasure to the CMF of interest list and categorized them appropriately. The result of this process was a list of countermeasure categories that covered both CMFs currently available in the Clearinghouse as well as those countermeasures that have been identified and documented by state DOTs for which CMFs may not be currently available. The research team then identified similar countermeasures and organized them in countermeasure subcategories. For example, all CMFs related to changing the spacing or density of driveways along roadways were placed in the same group of countermeasures âChange Driveway Spacing/Densityâ, created under the Access Management category. The team also identified the applicability of each CMF by some or all of the following (as applicable and available): ⢠Area type: All, Urban/Suburban, and Rural ⢠Intersection configuration: 3-leg, 4-leg, and more than 4-leg ⢠Intersection traffic control: Signal, Stop, and Roundabout ⢠Number of lanes: 2-lane, 4-lane, and others P-5
⢠Crash severity: Based on the KABCO scale, five levels of severity are possible: Fatal (K), Incapacitating Injury (A), Non-Incapacitating Injury (B), Possible Injury (C), and Property Damage Only (PDO). CMFs are provided for the following crash severity categories: KABCO, KABC, KAB, and PDO. For each subcategory of countermeasures, the average, maximum and minimum CMF ratings were determined. These rating values would help determine the overall quality of CMFs under each subcategory. The team also counted the number of CMFs currently available for each subcategory, separated by area type, intersection configuration, traffic control type, number of lanes, where applicable, as well as crash severity. These CMF counts help determine the gaps in terms of quantity (i.e., subcategories with no CMFs). Overall, the research team categorized and scored 7,407 CMFs from the CMF Clearinghouse that have been reviewed and rated under Task 7 of this project. After summarizing all available CMFs and their mean, maximum and minimum CMF ratings, and quantity (number of CMFs by each subcategory), the research team conducted a search into ongoing research efforts, primarily focused on NCHRP and FHWA, for potential CMFs that could be developed from these studies. The team identified several active and more recently completed NCHRP projects that appear to be related to the 18 countermeasure categories and might produce more CMFs to fill some of the gaps. The team also searched the list of recent FHWA Task Order and reached out to FHWA for additional information on recently completed and ongoing CMF development efforts. Overall, the team identified a total of 8 FHWA task orders that will likely produce more CMFs. It is important to note that a single project may cover more than one category. Inevitably, in this process there are duplications due to semantic differences in identifying countermeasures within and outside the Clearinghouse. Footnotes are provided where such duplications are identified but it is nevertheless still possible that an identified gap for a non-Clearinghouse CMF may be filled by definitive information on CMFs that have a different name in the Clearinghouse. Similarly, it is possible that an identified gap for a Clearinghouse CMF may be filled by definitive information on CMFs that have a different name and fall under a different Clearinghouse category. In short, the gaps identified here will need confirmation as such before research to fill the gap is considered. The following sections provide more detailed discussion of the analysis findings for each of the above 18 categories. They consist of tables that provide summary information for each countermeasure to facilitate the identification of potential gaps. The summary information includes number of CMFs in the Clearinghouse, the range of ratings for these CMFs and the number of CMFs applicable to each area type and crash severity level. Finally, it should be emphasized that evaluating the viability of research for filling the identified gaps was beyond the scope of this exercise. 2. ACCESS MANAGEMENT 2.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 670 CMFs in the CMF Clearinghouse that could be categorized under Access Management. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 1. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The P-6
table also includes the number of CMFs in each subcategory that are applicable to different area types and crash severity levels. Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 2.2 Active/Recent Research Projects The research team identified three active/recent projects from which CMFs are expected to fill some gaps related to this category: ⢠NCHRP 17-74: Application of Crash Modification Factors for Access Management ⢠FHWA-HRT-17-084: Safety Evaluation of Corner Clearance at Signalized Intersections at Signalized Intersections. ⢠FHWA-HRT-17-064: Safety Evaluation of Turning Movement Restrictions at Stop-Controlled Intersections. P-7
Table 1. CMFs of Interest for Access Management Number of CMFs Number of CMFs Applicable by CMF Ratings Segment / Number of Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban AM1 Change Driveway Spacing/Density Segment 24 105.8 115 70 0 17 3 16 6 0 2 AM2 Change Driveway Type Segment 87 37.9 85 20 0 87 0 33 24 0 30 AM3a Change Driveway Width Segment 1 85.0 85 85 0 1 0 1 0 0 0 AM3b Change Driveway Width Intersection 1 70.0 70 70 0 0 0 1 0 0 0 AM4 Change Number of Driveway Entry Lanes Segment 1 75.0 75 75 0 1 0 1 0 0 0 AM5a Change Median Width Segment 143 103.7 140 50 1 73 62 117 25 1 0 AM5b Change Median Width Intersection 1 135.0 135 135 0 1 0 1 0 0 0 AM6a Install Median Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 AM6b Install Median Intersection 2 85.0 85 85 1 1 0 2 0 0 0 AM7a Install Raised Median Segment 145 47.4 130 20 0 136 7 83 34 10 18 AM7b Install Raised Median Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 AM8a Install Flush Median Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 AM8b Install Flush Median Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 AM9 Replace Two-Way Left-Turn Lane with Raised Median Segment 10 95.5 115 50 0 6 0 7 2 0 1 AM10 Flatten Entrance Slopes Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 AM11 Adjust Driveways Near Intersection Intersection 29 136.9 150 80 0 0 0 25 4 0 0 AM12a Create/Covert to Directional Median Openings Segment 15 84.7 100 60 0 14 0 5 4 4 2 AM12b Create/Covert to Directional Median Openings Intersection 1 10.0 10 10 0 0 0 1 0 0 0 AM13a Change Intersection Density/Spacing Segment 18 108.1 115 80 0 18 0 12 1 4 1 AM13b Change Intersection Density/Spacing Intersection 14 91.1 125 75 0 14 0 14 0 0 0 AM14a Change Median Opening Density Segment 5 110.0 115 90 0 5 0 3 1 0 1 AM14b Change Median Opening Density Intersection 1 75.0 75 75 1 0 0 1 0 0 0 AM15a Convert Driveway to Regular Intersection Segment 1 85.0 85 85 0 1 0 1 0 0 0 AM15b Convert Driveway to Regular Intersection Intersection 3 88.3 95 75 3 0 0 3 0 0 0 AM16 Convert to Right-In-Right-Out (RIRO) Operations Intersection 9 88.3 105 75 0 9 0 6 3 0 0 AM17a Convert Two-Way to One-Way Segment 1 80.0 80 80 0 1 0 1 0 0 0 AM17b Convert Two-Way to One-Way Intersection 1 120.0 120 120 0 1 0 1 0 0 0 P-8
Number of CMFs Number of CMFs Applicable by CMF Ratings Segment / Number of Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban Increase Separation Between Driveway and Downstream U- AM18 Intersection 2 110.0 110 110 0 0 0 2 0 0 0 Turn Convert frontage road from two-way operation to one-way AM19a Segment 8 53.4 72 30 0 0 0 0 7 1 0 operation Convert frontage road from two-way operation to one-way AM19b Intersection 4 60.0 60 60 0 0 0 2 1 1 0 operation AM20a Change freeway ramp density/spacing Segment 32 85.5 130 0 12 8 0 9 23 0 0 AM20b Change freeway ramp density/spacing Intersection 3 78.3 85 75 0 0 0 3 0 0 0 AM21 Change Roadway Cross-Section at Driveways Segment 80 36.3 40 20 0 80 0 26 27 0 27 AM22a Convert Open Median to Two-Way-Left-Turn Lane Segment 1 85.0 85 85 0 1 0 1 0 0 0 AM22b Convert Open Median to Two-Way-Left-Turn Lane Intersection 1 70.0 70 70 0 0 0 1 0 0 0 AM23 Convert HOV to HOT Lanes Segment 24 81.1 110 25 0 6 0 13 4 3 4 Presence of 3-leg Intersections versus 4-leg Intersections AM24 Intersection 2 82.5 85 80 0 2 0 2 0 0 0 (Corridor level) P-9
3. ADVANCED TECHNOLOGY AND INTELLIGENT TRANSPORTATION SYSTEMS 3.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 509 CMFs in the CMF Clearinghouse that could be categorized under Advanced Technology and Intelligent Transportation Systems . After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 2. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types and crash severity levels. The following countermeasure subcategory was initially proposed but eventually deleted from the final list presented in Table 2 because there is an overlap with other more specific subcategories: ⢠Install Changeable Message Signs Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 3.2 Active/Recent Research Projects The research team identified two active NCHRP projects. While it is not clear what specific CMFs will be developed based on the project descriptions or on available information on research progress, any CMFs resulting from these projects might fill some gaps related to this category: ⢠NCHRP 17-95: Crash Modification Factors (CMFs) for Intelligent Transportation System (ITS) Applications ⢠NCHRP 03-135: Wrong-Way Driving Solutions, Policy, and Guidance P-10
Table 2. CMFs of Interest for Advanced Technology and Intelligent Transportation Systems Number of CMFs Applicable Number of CMFs Applicable by CMF Ratings Segment / Number of by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Urban Ma Mi Related CMF-CH Mean All /Suburba Rural KABCO KABC KAB PDO x n n ITS1 Implement Active Traffic Management Strategies Segment 18 95.8 115 85 0 6 0 9 9 0 0 Install Changeable Speed or Crash Ahead Warning ITS2 Segment 8 78.1 105 45 0 6 0 5 2 0 1 Signs ITS3 Install Changeable Warning Signs Segment 7 12.1 65 0 0 0 5 5 1 0 1 ITS4a Install Red-light Cameras Segment 10 82.5 105 10 0 0 0 10 0 0 0 ITS4b Install Red-light Cameras Intersection 107 76.0 145 5 30 35 0 76 24 5 2 ITS5a Deactivate Red-light Cameras Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ITS5b Deactivate Red-light Cameras Intersection 16 89.7 115 50 0 16 0 6 6 4 0 ITS6a Install Speed Enforcement Camera/System Segment 233 100.4 145 20 22 151 33 97 61 27 48 ITS6b Install Speed Enforcement Camera/System Intersection 7 112.9 130 70 0 5 0 3 2 0 2 ITS7 Remove Speed Enforcement Camera/System Segment 6 67.0 80 57 0 0 0 2 2 0 2 ITS8 Install Dynamic Speed Feedback Signs Segment 5 93.0 110 25 0 0 5 5 0 0 0 Install Combined Speed Enforcement & Red-light ITS9a Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 Camera Install Combined Speed Enforcement & Red-light ITS9b Intersection 25 58.0 65 45 21 2 2 22 0 3 0 Camera ITS10 Install Toll Collection System Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ITS11 Install Ramp Meters1 Segment 1 50.0 50 50 0 1 0 1 0 0 0 ITS12 Install Long Vehicle Detection Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 Implement Incident Management to Reduce Incident ITS13 Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 Duration Time ITS14 Install Changeable "Queue Ahead" Warning Signs Segment 2 105.0 105 105 0 2 0 0 1 0 1 ITS15 Install Wrong Way Driver Advanced Technology Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ITS16 Install a "Vehicles Entering When Flashing" Sign Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 a ITS16 Install a "Vehicles Entering When Flashing" Sign Intersection 16 93.1 110 80 16 0 0 8 4 4 0 b ITS17 Install Red-light Indicator Lights Intersection 47 129.8 145 115 0 0 0 36 11 0 0 1 May be addressed in NCHRP 17-95 P-11
4. HIGHWAY ALIGNMENT 4.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 147 CMFs in the CMF Clearinghouse that could be categorized under Highway Alignment. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 3. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types, number of lanes, and crash severity levels. The following countermeasure subcategory was initially proposed but eventually deleted from the final list presented in Table 3 because there is an overlap with other more specific subcategories: ⢠Make Geometric Improvements Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 4.2 Active/Recent Research Projects The research team did not find any ongoing projects from NCHRP or FHWA that would likely produce more CMFs related to this category. P-12
Table 3. CMFs of Interest for Alignments Number of CMFs Number of CMFs Number of CMFs Applicable by CMF Ratings Applicable by Segment / Number of Applicable by Area Type Crash Severity Number of Lanes CM ID Countermeasure Name Intersectio CMFs in Urban n Related CMF-CH KABC KAB 2- 4- Mean Max Min All /Suburba Rural KAB PDO Other O C Lane Lane n AL1a Change Horizontal Alignment Segment 90 85.0 135 0 4 8 59 44 39 0 7 49 21 4 Change Horizontal AL1b Intersection 1 30.0 30 30 0 0 1 1 0 0 0 0 1 0 Alignment AL2 Change Vertical Alignment Segment 17 66.8 115 40 2 0 11 5 9 0 3 11 1 1 AL3 Improve Superelevation Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Change Stopping Sight Distance on AL4 Segment 2 87.5 95 80 0 0 2 1 1 0 0 2 0 0 Crest Vertical Curve Change Horizontal Curve Radius, AL5 Segment 17 103.9 145 70 0 0 17 12 5 0 0 17 0 0 Posted Speed and Superelevation Change Horizontal Alignment at AL6 Segment 20 88.0 95 75 0 0 20 0 10 0 10 20 0 0 Vertical Curve Presence of Reverse Curve AL7 Segment 1 60.0 60 60 0 0 0 1 0 0 0 0 0 0 (Motorcycle Safety) P-13
5. BICYCLISTS AND PEDESTRIANS 5.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 241 CMFs in the CMF Clearinghouse that could be categorized under Bicyclists and Pedestrians. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 4. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different types of traffic control and crash severity levels. The following countermeasure subcategories were initially proposed but eventually deleted from the final list presented in Table 4 because they are too generic and/or there is an overlap with other subcategories: ⢠Install Advanced Yield or Stop markings and Signs at Pedestrian Crossing ⢠Install Pedestrian Crossing ⢠Install Pedestrian Structure Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 5.2 Active/Recent Research Projects The research team identified six active/recently completed NCHRP projects and FHWA Task Orders. While it is not always clear from the project descriptions what specific CMFs will be developed, any CMFs resulting from these projects might fill some gaps related to this category: ⢠NCHRP 15-74: Safety Evaluation of On-Street Bicycle Facility Design Features ⢠NCHRP 17-84: Pedestrian and Bicycle Safety Performance Functions for the Highway Safety Manual ⢠FHWA Task Order: ELCSI-PFS, Phase XII - Safety Evaluations of Innovative Intersection Designs for Pedestrian and Bicyclists ⢠FHWA Task Order, ELCSI-PFS, Phase XI- Developing Crash Modification Factors for Bicycle Treatments at Intersections. ⢠FHWA Task Order: Development of Pedestrian-Intersection Crash Modification Factors ⢠FHWA Task Order: Safety Study on Pedestrian Crossing Warning MUTCD W11-2 sign with Embedded Light Emitting Diodes (LEDs) The team also identified another FHWA Task Order: Pre-Crash Modification Factors Study for Curb Extensions and Bicycle Specific Intersection Markings that will likely lead to development of new CMFs under this category. Under this task order, the effort will be focused on conducting literature reviews and collecting existing data on how curb extensions and bicycle specific intersection markings influence the number and type of crashes at intersections. However, the results of this effort may eventually lead to the development of CMFs for these intersection treatments. P-14
Table 4. CMFs of Interest for Bicyclists and Pedestrians Number of CMFs Number of CMFs Applicable by Number of CMFs Applicable Segment / Number of CMF Ratings Applicable by Area Type Crash Severity by Traffic Control CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO Signal Stop Roundabout /Suburban PB1a Change Sidewalk Width Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 N/A N/A N/A PB1b Change Sidewalk Width Intersection 2 82.5 90 75 0 0 0 1 1 0 0 1 0 0 PB2a Install Bicycle Lane Segment 103 31.7 110 10 1 28 0 84 17 0 2 N/A N/A N/A PB2b Install Bicycle Lane Intersection 28 45.5 80 20 0 16 0 20 7 1 0 2 1 0 PB3 Change Bike-Lane Width Segment 6 105.0 105 105 0 6 0 4 2 0 0 N/A N/A N/A Install Dedicated Bicycle PB4a Segment 6 36.7 45 35 0 6 0 0 6 0 0 N/A N/A N/A Facility Install Dedicated Bicycle PB4b Intersection 20 41.2 60 35 0 20 0 16 4 0 0 13 0 0 Facility PB6 Install Bicycle Box1 Intersection 1 N/A N/A N/A 0 1 0 1 0 0 0 1 0 0 PB7 Install Bicycle Signal Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Install Raised Bicycle PB8 Intersection 2 77.5 80 75 0 1 0 1 1 0 0 0 0 0 Crossings PB9 Install Sidewalk Barrier Segment 6 59.2 80 50 0 6 0 4 0 2 0 N/A N/A N/A Install Dedicated Bicycle PB10 Facility and Cyclist Priority Intersection 7 69.3 80 60 0 7 0 7 0 0 0 0 0 0 at Intersection Install Combination of Additional Travel lanes, PB11 Intersection 4 61.3 65 60 0 4 0 4 0 0 0 0 0 0 Raised Islands and Left- turn Lanes (Bicycle) Presence of Speed PB12a Restriction Devices Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 N/A N/A N/A (Bicyclist Safety) Presence of Speed PB12b Restriction Devices Intersection 1 80.0 80 80 0 0 0 1 0 0 0 1 0 0 (Bicyclist Safety) Install Pedestrian Hybrid PB13a Beacon or Stop Markings Segment 1 95.0 95 95 0 1 0 1 0 0 0 N/A N/A N/A and Signs2 Install Pedestrian Hybrid PB13b Beacon or Stop Markings Intersection 3 93.3 100 80 0 3 0 2 1 0 0 0 0 0 and Signs2 PB14 Install Raised Intersection Intersection 3 76.7 80 75 0 1 0 1 1 0 1 1 0 0 PB15 Install Sidewalk Segment 6 78.3 105 50 0 6 0 4 0 2 0 N/A N/A N/A P-15
Number of CMFs Number of CMFs Applicable by Number of CMFs Applicable Segment / Number of CMF Ratings Applicable by Area Type Crash Severity by Traffic Control CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO Signal Stop Roundabout /Suburban PB16 Implement Barnes Dance Intersection 2 57.5 60 55 0 2 0 2 0 0 0 2 0 0 PB17 Install RRFB Segment 3 53.3 85 10 2 1 0 3 0 0 0 N/A N/A N/A Construct Pedestrian and/or PB18 Bicycle Overpass or Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 N/A N/A N/A Underpass3 PB19 Install Pedestrian Fencing Segment 8 76.3 90 70 0 0 0 8 0 0 0 N/A N/A N/A Separate Pedestrians from PB20 Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 N/A N/A N/A Vehicle Traffic on Bridge Install Actuated Overhead PB21 Flasher for a Pedestrian Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 N/A N/A N/A Location PB22a Improve Pedestrian Signals 4 Segment 4 75.0 90 70 0 0 0 4 0 0 0 N/A N/A N/A PB22b Improve Pedestrian Signals 4 Intersection 2 65.0 65 65 0 2 0 2 0 0 0 2 0 0 Add Exclusive Pedestrian PB23a Segment 4 70.0 85 65 0 0 0 4 0 0 0 N/A N/A N/A Phasing 5 Add Exclusive Pedestrian PB23b Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Phasing 5 PB24 Install Crosswalk Intersection 2 77.5 80 75 1 0 0 2 0 0 0 1 1 0 PB25a Install Raised Crosswalk Segment 3 75.0 75 75 0 3 0 0 3 0 0 N/A N/A N/A PB25b Install Raised Crosswalk Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Install Pedestrian Refuge PB26 Intersection 3 91.6 115 70 3 0 0 3 0 0 0 3 0 0 Island Install High-Visibility PB27a Segment 1 110.0 110 110 0 1 0 1 0 0 0 N/A N/A N/A Crosswalks Install High-Visibility PB27b Intersection 2 60.0 65 55 0 2 0 2 0 0 0 0 0 0 Crosswalks PB28a Install a Bus Shelter Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 N/A N/A N/A PB28b Install a Bus Shelter Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Convert to Puffin PB29 Intersection 7 77.1 100 55 0 0 0 0 7 0 0 7 0 0 Pedestrian Crossing Install Parallelogram- PB30 Intersection 2 90.0 95 85 0 2 0 2 0 0 0 0 0 0 shaped Pavement Markings Install Pedestrian Hybrid Beacon with Advanced PB31 Segment 3 108.3 125 90 0 3 0 3 0 0 0 N/A N/A N/A Yield or Stop Markings and Signs 6 P-16
Number of CMFs Number of CMFs Applicable by Number of CMFs Applicable Segment / Number of CMF Ratings Applicable by Area Type Crash Severity by Traffic Control CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO Signal Stop Roundabout /Suburban 1 Could not be rated in the Clearinghouse. 2 Separate CMFs estimated in NCHRP Project 17-56 and Report 841 for uncontrolled pedestrian crossings. Includes RRFB. 3 Gap pertains to bicycles. Clearinghouse does have CMFs for:â Install pedestrian overpass/underpassâ and âInstall pedestrian overpass/underpass (unsignalized intersection"). 4 Also identified in Table 9. Related to âpedestrian countdown signalsâ for which CMFs from a recent FHWA study may not be presented in the Clearinghouse. See: https://www.fhwa.dot.gov/publications/research/safety/19045/19045.pdf 5 Related to leading pedestrian interval for with there are CMFs in the Clearinghouse based in a recent FHWA study. 6 See Note 2. P-17
6. HIGHWAY DELINEATION 6.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 276 CMFs in the CMF Clearinghouse that could be categorized under Highway Delineation. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 5. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types, number of lanes, and crash severity levels. The following countermeasure subcategories were initially proposed but eventually deleted from the final list presented in Table 5 because there is an overlap with other subcategories: ⢠Restripe with Paint ⢠Restripe with Thermoplastic Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 6.2 Active/Recent Research Projects The research team identified two active NCHRP projects. While it is not clear from the project descriptions what specific CMFs will be developed, any CMFs resulting from these projects might fill some gaps related to this category: ⢠NCHRP 05-21: Safety and Performance Criteria for Retroreflective Pavement Markers ⢠NCHRP 15-68: Effective Low-Noise Rumble Strips P-18
Table 5. CMFs of Interest for Delineation Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Number of Lanes Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane Install Standard Edge Line and/or D1 Segment 28 64.3 115 30 1 2 25 21 4 1 2 0 0 0 Center Line Markings D2 Apply Thermoplastic Markings Segment 21 126.5 137 110 0 0 21 18 3 0 0 0 0 0 D3a Apply Paint Markings Segment 1 30.0 30 30 0 1 0 1 0 0 0 0 0 0 D3b Apply Paint Markings Intersection 1 85.0 85 85 1 0 0 1 0 0 0 0 1 0 D4 Install Wide Pavement Markings Segment 73 97.6 120 20 0 6 67 29 28 12 4 0 0 0 D5 Install Raised Pavement Markers Segment 21 87.6 140 40 0 0 21 21 0 0 0 0 0 0 Install Raised Pavement Markers D6 Segment 4 36.3 75 10 0 0 4 3 1 0 0 0 0 0 and Transverse Rumble Strips Install Raised Pavement Markers, D7 Transverse Rumble Strips and Segment 3 10.0 10 10 0 0 3 3 0 0 0 0 0 0 Transverse Markings Improve Pavement Marking D8 Segment 10 65.0 90 30 0 0 5 10 0 0 0 0 0 0 Retroreflectivity Improve Pavement Marking to Wet- D9 Segment 54 116.6 135 90 0 0 0 46 8 0 0 0 0 0 Reflective Markings D10 Restripe with Epoxy Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 D11 Restripe with Tape Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Provide "Stop Ahead" Pavement D12a Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Markings Provide "Stop Ahead" Pavement D12b Intersection 30 106.5 130 70 0 0 30 13 11 0 6 0 30 0 Markings D13 Install Delineators Segment 5 78.0 120 60 0 0 4 2 2 0 1 0 0 0 D14 Install Profile Edge Line Markings 1 Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 D15 Install Profile Center Line Markings Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 D16 Install Distance Markers Segment 1 105.0 105 105 0 0 0 0 1 0 0 0 0 0 Install In-lane Warning Pavement D17 Segment 6 85.0 115 10 0 0 0 5 1 0 0 0 0 0 Markings Install Lighted Pavement Marking D18 Segment 1 10.0 10 10 0 0 0 1 0 0 0 0 0 0 System Install Supplemental Pavement D19 Intersection 9 100.6 105 95 0 0 9 3 3 0 3 0 0 0 Markings at Intersection P-19
Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Number of Lanes Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane Install Transverse Pavement D20a Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Markings Install Transverse Pavement D20b Intersection 7 63.6 75 55 0 0 0 6 1 0 0 0 0 7 Markings Install Edgelines and Directional D21 Segment 1 75.0 75 75 0 0 1 0 1 0 0 0 0 0 Markings 1 Also referred to as âprofiled thermoplastic pavement markingsâ and is identified as such in the Clearinghouse with CMFs based on a definitive FHWA study. See: https://www.fhwa.dot.gov/publications/research/safety/17075/17075.pdf P-20
7. HIGHWAY LIGHTING 7.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 92 CMFs in the CMF Clearinghouse that could be categorized under Highway Lighting. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 6. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types and crash severity levels. Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 7.2 Active/Recent Research Projects The research team did not find any ongoing projects from NCHRP or FHWA that would likely produce more CMFs related to this category. P-21
Table 6. CMFs of Interest for Lighting Number of CMFs Applicable Number of CMFs Applicable by Segment / Number of CMF Ratings by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban LT1a Modify/Improve Lighting Segment 3 111.7 115 105 0 1 0 3 0 0 0 LT1b Modify/Improve Lighting Intersection 16 93.4 120 75 0 16 0 10 6 0 0 LT2 Provide Lighting Segment 48 87.7 120 65 21 12 13 12 23 6 7 LT3 Provide Intersection Lighting Intersection 25 84.0 110 50 3 4 9 14 5 3 3 P-22
8. INTERCHANGES/RAMPS 8.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 137 CMFs in the CMF Clearinghouse that could be categorized under Interchanges/Ramps. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 7. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types and crash severity levels. Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 8.2 Active/Recent Research Projects The research team identified two active NCHRP projects and one FHWA task order. While it is not clear from the project descriptions what specific CMFs will be developed, any CMFs resulting from these projects might fill some gaps related to this category: ⢠NCHRP 15-56: Guidelines for Selecting Ramp Design Speeds ⢠NCHRP 15-66: Operational Performance and Safety Effects of Arterial Weaving Sections ⢠FHWA Task Order: Safety Comparisons between Interchange Types P-23
Table 7. CMFs of Interest for Interchanges Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban IC1a Install Grade Separation Segment 3 50.0 50 50 1 0 0 1 1 1 0 IC1b Install Grade Separation Intersection 8 43.8 95 20 0 0 0 5 2 0 1 IC2 Modify Speed Change Lane Design Segment 9 63.9 115 35 0 0 0 9 0 0 0 IC3 Modify Number of Lane Changes at Merge/Diverge Area Segment 4 98.8 115 90 0 0 0 2 0 2 0 IC4a Modify Number of Lanes on Ramp Segment 5 91.0 115 30 0 0 0 3 0 2 0 IC4b Modify Number of Lanes on Ramp Intersection 1 105.0 105 105 0 0 0 1 0 0 0 IC5 Add Acceleration or Deceleration Lane Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 IC6 Extend Acceleration or Deceleration Lane 1 Segment 2 105.0 105 105 0 0 0 2 0 0 0 IC7a Provide Auxiliary Lane Between Entrance and Exit Ramp Segment 4 0.0 0 0 0 0 0 3 1 0 0 IC7b Provide Auxiliary Lane Between Entrance and Exit Ramp Intersection 4 102.5 105 95 0 0 0 3 1 0 0 IC8 Change Ramp Type/Length Segment 7 72.9 115 30 0 0 0 7 0 0 0 Convert Diamond Interchange to Diverging or Double IC9a Segment 6 56.7 80 45 0 6 0 5 1 0 0 Cross Diamond Interchange Convert Diamond Interchange to Diverging or Double IC9b Intersection 52 62.2 95 10 0 12 0 36 7 1 8 Cross Diamond Interchange Implement Left-hand Merge and Downstream Lane Shift IC10 Segment 2 55.0 60 50 0 0 2 1 1 0 0 (Iowa Weave) IC11 Provide Median on Interchange Cross-Road Intersection 1 100.0 100 100 0 0 0 1 0 0 0 IC12 Design Overpass versus Underpass at Interchange Segment 1 10.0 10 10 0 0 0 1 0 0 0 IC13 Provide Diamond Interchange Segment 7 18.6 30 10 0 0 0 7 0 0 0 IC14 Provide Cloverleaf Ramp Instead of Long Ramp Segment 1 30.0 30 30 0 0 0 1 0 0 0 IC15 Provide On-Ramp Segment 14 70.7 115 50 0 0 14 11 3 0 0 IC16 Implement Ramp Reversal Segment 4 16.3 30 0 0 4 0 1 1 1 1 IC17 Provide Median on Interchange Cross-Road Intersection 1 100.0 100 100 0 0 0 1 0 0 0 IC18 Provide Tight Urban Diamond Interchange (TUDI) Segment 1 10.0 10 10 0 0 0 1 0 0 0 IC19 Presence of Left-side Off-Ramp Segment 1 95.0 95 95 0 0 0 1 0 0 0 1There are several CMFs for subcategories based on value of change in length and âafter periodâ length. Note: The iSATe software has the capability to directly estimate the safety of design options rather than apply some Clearinghouse CMF. P-24
9. INTERSECTION GEOMETRY 9.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 868 CMFs in the CMF Clearinghouse that could be categorized under Intersection Geometry. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 8. The table presents the mean, max and min CMF rating scores as well as numbers of CMFs available by area type, type of traffic control, number of lanes, crash severity levels, and intersection configuration. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The following countermeasure subcategories were initially proposed but eventually deleted from the final list presented in Table 8 because they are too generic and/or there is an overlap with other subcategories: ⢠Modify Intersection Geometry ⢠Provide Painted Channelized Left Turn Lane Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 9.2 Active/Recent Research Projects The research team found one ongoing FHWA project that would likely produce more CMFs related to mini- roundabouts and improvements related to wrong-way driving and a forthcoming NCHRP FY2022 project: ⢠ELCSI-PFS, Phase XI: Safety Evaluations of Mini-Roundabouts and Wrong Way Driving Improvements, final report expected soon. ⢠NCHRP 17-108: Develop Crash Modification Factors (CMFs) for Alternative Intersections, Including Displaced Left-Turn (DLT), Median U-Turn (MUT), and Restricted Crossing U-Turn (RCUT) P-25
Table 8. CMFs of Interest for Intersection Geometry Number of CMFs Number of CMFs No. Number of CMFs Number of CMFs Applicable by Number of CMFs Applicable Applicable by CMF Ratings Applicable by of Applicable by Area Type Crash Severity by Traffic Control Intersection Number of Lanes CM Seg / Int CMFs Configuration CM Name ID Related in More CMF- Urban 2- 4- 3- 4- than Mean Max Min All Rural KABCO KABC KAB PDO Other Signal Stop Roundabout CH /Suburban Lane Lane Leg Leg 4- Leg Convert IG1a Intersection to Intersection 258 67.0 140 10 83 93 44 158 74 18 8 65 8 60 19 38 82 66 108 0 Roundabout Convert IG1b Intersection to Segment 17 115.0 135 35 0 0 0 17 0 0 0 0 0 0 0 0 0 0 0 0 Roundabout Convert to IG2 Roundabout Intersection 9 87.8 95 85 9 0 0 3 3 0 3 3 0 3 0 0 9 0 0 0 Interchange Add Quadrant IG3 Roadway to Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Intersection Change IG4 Intersection Intersection 9 85.0 85 85 0 4 5 9 0 0 0 4 1 1 0 9 0 4 5 0 Angle Convert 4-Leg Intersection to IG5a Intersection 11 66.4 105 20 1 6 4 3 3 1 4 0 4 0 0 4 0 4 11 0 Two 3-Leg Intersections Convert 4-Leg Intersection to IG5b Segment 7 10.7 15 10 0 0 0 7 0 0 0 0 0 0 0 0 0 0 0 0 Two 3-Leg Intersections Convert Intersection to IG6 Intersection 1 95.0 95 95 0 0 0 1 0 0 0 0 0 0 1 0 0 0 1 0 Continuous Flow Intersection Convert IG7 Intersection to Intersection 1 130.0 130 130 0 1 0 1 0 0 0 0 1 1 1 0 0 0 0 0 Median U-Turn Convert IG8a Intersection to Intersection 104 39.3 120 10 9 25 28 77 11 7 9 0 52 10 14 71 0 19 77 0 RCUT/J-Turn Convert IG8b Intersection to Segment 27 40.6 45 40 0 0 0 23 0 2 2 0 0 0 0 0 0 0 0 0 RCUT/J-Turn Convert T- Intersection to IG9 Continuous Intersection 3 101.7 105 95 0 0 0 2 1 0 0 0 0 0 3 0 0 3 0 0 Green-T Intersection P-26
Number of CMFs Number of CMFs No. Number of CMFs Number of CMFs Applicable by Number of CMFs Applicable Applicable by CMF Ratings Applicable by of Applicable by Area Type Crash Severity by Traffic Control Intersection Number of Lanes CM Seg / Int CMFs Configuration CM Name ID Related in More CMF- Urban 2- 4- 3- 4- than Mean Max Min All Rural KABCO KABC KAB PDO Other Signal Stop Roundabout CH /Suburban Lane Lane Leg Leg 4- Leg Change/Improve IG10 Intersection Intersection 19 74.5 120 20 2 4 0 10 5 2 2 0 0 0 2 2 0 6 8 0 Sight Distance Modify IG11 Roundabout Intersection 16 78.8 80 70 0 16 0 6 5 0 5 0 0 0 0 0 16 0 0 0 Geometry Provide Left Turn/Median IG12a Intersection 5 18.0 30 10 0 0 5 4 1 0 0 0 0 0 0 5 0 0 5 0 Acceleration Lane Provide Left Turn/Median IG12b Segment 17 10.3 15 10 0 0 0 17 0 0 0 0 0 0 0 0 0 0 0 0 Acceleration Lane Change Number of Lanes on IG13 Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Intersection Approach Change Turn IG14 Segment 1 90.0 90 90 0 1 0 1 0 0 0 0 1 1 0 0 0 0 0 0 Lane Length Install Curb IG15 Extensions/Bulb Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Outs Install Reduced Left-Turn IG16 Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Conflict Intersection Install IG17 Intersection 8 89.4 105 75 0 0 8 0 5 0 3 0 0 0 0 0 0 3 5 0 Channelization Convert Unsignalized IG18 Superstreet to a Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Signalized Superstreet Provide IG19 Channelized Intersection 11 89.1 115 75 0 0 11 4 4 0 3 2 0 0 0 4 0 3 8 0 Left Turn Lane Provide IG20 Channelized Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Right Turn Lane P-27
Number of CMFs Number of CMFs No. Number of CMFs Number of CMFs Applicable by Number of CMFs Applicable Applicable by CMF Ratings Applicable by of Applicable by Area Type Crash Severity by Traffic Control Intersection Number of Lanes CM Seg / Int CMFs Configuration CM Name ID Related in More CMF- Urban 2- 4- 3- 4- than Mean Max Min All Rural KABCO KABC KAB PDO Other Signal Stop Roundabout CH /Suburban Lane Lane Leg Leg 4- Leg Modify/Improve Angle of IG21 Intersection 4 108.8 110 105 0 0 0 3 1 0 0 4 0 4 0 0 0 0 0 0 Channelized Right Turn Lane Add Left- or IG22 Right-Turn By- Intersection 3 33.3 40 30 0 0 3 1 1 0 1 0 0 0 0 3 0 3 3 0 Pass Lanes Improve Left- Turn Lane IG23 Intersection 21 42.4 115 10 0 2 15 15 3 1 2 0 15 0 2 15 0 0 19 0 Offset to Create Positive Offset Provide Left IG24 Intersection 51 104.4 135 0 18 21 9 35 15 0 1 18 3 3 30 19 0 19 32 0 Turn Lane Increase IG25 Number of Left Intersection 2 105.0 110 100 0 0 2 2 0 0 0 2 0 0 0 0 0 0 0 0 Turn Lanes Provide Right IG26 Intersection 209 86.2 130 50 200 4 0 207 2 0 0 196 1 3 10 6 0 8 5 0 Turn Lane Increase IG27 Number of Right Intersection 2 90.0 90 90 0 0 2 2 0 0 0 2 0 0 0 0 0 0 0 0 Turn Lanes Provide Offset IG28a Intersection 19 15.3 30 10 0 0 19 14 2 1 2 0 0 0 0 19 0 0 19 0 Right Turn Lane Provide Offset IG28b Segment 7 12.9 30 10 0 0 0 7 0 0 0 0 0 0 0 0 0 0 0 0 Right Turn Lane Provide Right Turn IG29 Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Acceleration Lane Install Turn IG30 Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Arounds Change IG31 Intersection Intersection 7 107.9 115 90 0 5 2 4 3 0 0 0 0 0 2 5 0 1 6 0 Median Width Provide Channelizing Separator IG32 Intersection 4 10.0 10 10 0 0 4 3 1 0 0 0 0 4 0 4 0 0 4 0 Islands and Supplemental Stop Signs P-28
Number of CMFs Number of CMFs No. Number of CMFs Number of CMFs Applicable by Number of CMFs Applicable Applicable by CMF Ratings Applicable by of Applicable by Area Type Crash Severity by Traffic Control Intersection Number of Lanes CM Seg / Int CMFs Configuration CM Name ID Related in More CMF- Urban 2- 4- 3- 4- than Mean Max Min All Rural KABCO KABC KAB PDO Other Signal Stop Roundabout CH /Suburban Lane Lane Leg Leg 4- Leg Provide Left IG33 Turn Lane and Intersection 15 117.3 125 97 15 0 0 12 3 0 0 15 0 0 0 15 0 10 10 0 Install Signal 1 In principle the same as âRestricted Crossing U-Turn intersection (RCUT), J- turn intersectionâ, identified above. 2 May be related to Clearinghouse countermeasure: âPhysical channelization of right-turn lane on major roadâ. 3 In Clearinghouse as âInstall Median Acceleration Lanesâ. P-29
10. INTERSECTION TRAFFIC CONTROL 10.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 883 CMFs in the CMF Clearinghouse that could be categorized under Intersection Traffic Control. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 9. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types and crash severity levels. The following countermeasure subcategory was initially proposed but eventually deleted from the final list presented in Table 9 because there is an overlap with other subcategories: ⢠Install Temporary Traffic Circle Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 10.2 Active/Recent Research Projects The research team identified two active NCHRP projects and one recently completed FHWA Task Order. While it is not always clear from the project descriptions what specific CMFs will be developed, any CMFs resulting from these projects might fill some gaps related to this category: ⢠NCHRP 03-136: Evaluating the Performance of Right-Turn-On-Red Operation at Signalized Intersections (with single and dual right-turn lanes) ⢠NCHRP 03-125: Evaluation of Change and Clearance Intervals Prior to the Flashing Yellow Arrow Permissive Left-Turn Indication ⢠FHWA-HRT-20-072: Developing Crash Modification Factors for Adaptive Signal Control Technologies. P-30
Table 9. CMFs of Interest for Intersection Traffic Control Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban ITC1 Install Traffic Signal Intersection 115 82.2 145 20 22 22 26 83 18 7 7 ITC2 Install Adaptive Traffic Signal Intersection 33 90.9 115 70 0 33 0 15 14 2 2 ITC3 Convert Two-Way Stop to All-Way Stop Control Intersection 23 83.3 110 20 16 6 1 18 5 0 0 ITC4 All-Way Stop Control Installation with Overhead Flashers Intersection 8 78.7 85 55 8 0 0 6 2 0 0 ITC5 Coordinate Signals Segment 18 28.6 45 25 0 18 0 6 6 0 6 Improve Signal Head/Lens Visibility (Enlarge Existing Signal ITC6 Intersection 3 96.7 135 40 0 1 0 3 0 0 0 Head) ITC7 Install Additional Signal Head Intersection 1 25.0 25 25 0 1 0 1 0 0 0 ITC8 Install Additional Signal Head and Upgrade to 12-inch lenses Intersection 2 35.0 35 35 0 2 0 2 0 0 0 ITC9 Add Retroreflective Backplates Intersection 1 120.0 120 120 0 1 0 1 0 0 0 Improve Signal Visibility (combination of signal lens size, new ITC10 Intersection 11 124.5 150 100 0 11 0 3 4 0 4 backplates, reflective tape etc.) ITC11 Remove Unwarranted Signal Intersection 4 104.8 117 90 0 3 0 4 0 0 0 ITC12 Install Advance Dilemma Zone Protection System Intersection 6 52.5 75 20 0 0 1 4 2 0 0 ITC13 Install Emergency Vehicle Pre-Emption Systems Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 ITC14 Change Signal Mount Type Intersection 21 55.5 80 10 13 4 0 13 7 0 1 ITC15 Provide Flashing Beacon Intersection 15 101.7 130 20 12 2 1 14 1 0 0 ITC16a Change Signal Permissions/Protections Intersection 118 85.8 150 20 1 59 0 99 19 0 0 ITC16b Change Signal Permissions/Protections Segment 28 105.5 130 85 0 0 0 28 0 0 0 ITC17a Implement Flashing Yellow Arrow Intersection 32 87.5 140 45 3 10 0 23 9 0 0 ITC17b Implement Flashing Yellow Arrow Segment 24 96.3 110 85 0 0 0 24 0 0 0 ITC18 Change Signal Left-Turn Phasing Intersection 2 90.0 100 80 0 2 0 0 1 0 1 ITC19 Change Signal Left-Turn Phasing Consistency Intersection 6 34.2 45 20 0 0 0 6 0 0 0 ITC20a Change Signal/Phase Intervals Intersection 27 78.1 120 20 0 19 0 19 8 0 0 ITC20b Change Signal/Phase Intervals Segment 6 103.3 110 100 0 0 0 6 0 0 0 ITC21a Provide Split Phases Intersection 2 60.0 60 60 0 2 0 2 0 0 0 ITC21b Provide Split Phases Segment 4 66.3 70 65 0 0 0 4 0 0 0 ITC22 Install Pedestrian Countdown Timer Intersection 32 86.2 140 40 0 10 0 17 6 3 6 P-31
Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban ITC23 Replace Night-Time Flash with Steady Operation Intersection 9 105.6 120 30 3 3 0 7 2 0 0 ITC24 Modify Night-Time Flash Operation Period Intersection 3 90.0 90 90 0 0 0 2 1 0 0 ITC25 Install Pedestrian Signal Intersection 3 115.0 115 115 0 3 0 1 1 0 1 ITC26 Install Dynamic Red Extension Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 ITC27 Modify Traffic Signal Phasing Intersection 7 50.0 70 20 0 0 0 7 0 0 0 ITC28 Install Closed Loop Signal System Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 ITC29 Install Left Turn Yield Blank Out Sign Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 ITC30 Install Dynamic Signal Warning Flashers Intersection 16 24.4 30 10 0 0 16 10 2 2 2 Implement Systemic Signing and Marking Improvements at ITC31 Intersection 55 113.7 130 100 45 5 5 44 11 0 0 Stop-Controlled Intersections Implement Systemic Signing and Visibility Improvements at ITC32 Intersection 55 103.3 130 90 45 5 5 44 11 0 0 Signalized Intersections ITC33 Install Optically Programmed Signal Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 ITC34 Permit or Prohibit Right-Turn-On-Red Intersection 17 61.8 105 30 0 0 0 15 1 0 1 ITC35 Prohibit Left-Turns and/or U-Turns Intersection 4 60.0 70 50 0 4 0 4 0 0 0 ITC36 Provide Traffic Signal Actuation Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 ITC37 Provide Traffic Signal Time Lane Control Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 ITC38a Add/Adjust All-red Clearance Interval Intersection 12 75.4 120 20 0 4 0 10 2 0 0 ITC38b Add/Adjust All-red Clearance Interval Segment 1 10.0 10 10 0 0 0 1 0 0 0 ITC39 Convert Yield Signal Control to Signalized Control Intersection 129 52.4 85 35 0 126 0 129 0 0 0 ITC40 Install Box Span Signal Intersection 6 110.0 120 105 0 0 0 4 2 0 0 ITC41 Install Dual Red Signal Lenses Intersection 2 112.5 115 110 0 0 0 2 0 0 0 ITC42 Convert Stop Control to Yield Control Intersection 1 30.0 30 30 0 1 0 1 0 0 0 ITC43 Upgrade Traffic Signal Bulbs to LEDs Intersection 18 100.6 120 85 0 18 0 14 4 0 0 ITC44a Replace "Walk/Don't Walk" with Pedestrian Countdown Timer 1 Intersection 0 N/A N/A N/A 0 0 0 0 0 0 0 ITC44b Replace "Walk/Don't Walk" with Pedestrian Countdown Timer 1 Segment 1 0.0 0 0 0 0 0 1 0 0 0 ITC45 Restrict Left Turn or Right Turn (Transit Related) Intersection 3 115.0 115 115 0 3 0 3 0 0 0 ITC46 Permit/Restrict Through Movements Intersection 1 80.0 80 80 0 0 0 1 0 0 0 ITC47 Change Signal Phasing and Coordination Intersection 1 80.0 80 80 0 1 0 1 0 0 0 P-32
Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban 1 Should also be the same as âInstall pedestrian countdown timerâ listed earlier in the table. P-33
11. PAVEMENT TREATMENT AND RESURFACING 11.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 590 CMFs in the CMF Clearinghouse that could be categorized under Pavement Treatment and Resurfacing . After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 10. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types, number of lanes, and crash severity levels. Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 11.2 Active Research Projects The research team found one recently completed FHWA project that produced more CMFs related to high friction pavement treatments. The final study report will be reviewed and added to the CMF Clearinghouse: ⢠FHWA-HRT-20-61: Developing Crash-Modification Factors for High-Friction Surface Treatments ⢠There is also a recently started FHWA project that will produce additional CMF information: o DTFH6116D00041L/ 693JJ320F000259: Continuous Pavement Friction Measurement and Pavement Friction Management for Safety. P-34
Table 10. CMFs of Interest for Pavement Treatment and Resurfacing Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Number of Lanes Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane PTR1a Improve/Change Pavement Friction Segment 50 97.7 135 40 8 8 20 27 20 0 3 25 8 1 PTR1b Improve/Change Pavement Friction Intersection 38 123.2 130 65 37 1 0 38 0 0 0 0 0 0 PTR2 Pave Road Surface Segment 1 100.0 100 100 0 0 1 1 0 0 0 0 0 0 PTR3a Resurface Pavement Segment 29 89.8 130 40 0 21 0 14 13 2 0 0 0 0 PTR3b Resurface Pavement Intersection 4 123.8 150 50 0 3 0 1 2 1 0 0 0 0 PTR4 Change Surface Condition Segment 17 110.9 140 80 0 7 8 14 3 0 0 8 0 0 PTR5 Change Pavement Roughness Segment 3 80.0 80 80 0 0 0 3 0 0 0 0 0 0 Apply Grooved Pavement Skid PTR6 6 100.0 120 45 1 0 4 5 1 0 0 0 4 0 Treatment Segment PTR7 Apply Slurry Seal Segment 11 120.9 130 110 11 0 0 9 2 0 0 5 0 0 PTR8a Apply Micro-surfacing Segment 65 107.1 130 40 55 0 0 53 10 2 0 21 5 5 PTR8b Apply Micro-surfacing Intersection 2 50.0 50 50 0 0 0 2 0 0 0 0 0 0 PTR9 Apply Chip Seal Segment 83 116.7 130 100 82 0 0 70 13 0 0 32 21 21 Apply High Friction Surface PTR10 73 92.2 140 30 30 0 0 61 6 2 4 26 26 26 Treatment Segment Apply Thin Layer of Hot Mix PTR11 80 120.5 130 90 80 0 0 66 14 0 0 21 18 18 Asphalt Segment Apply Open Graded Friction PTR12 51 118.9 130 20 51 0 0 44 7 0 0 9 6 6 Course Segment Apply Ultrathin Bonded Wearing PTR13 42 114.6 130 100 42 0 0 35 7 0 0 6 0 0 Course Segment PTR14 Conduct Diamond Grinding Segment 34 120.9 130 95 34 0 0 28 6 0 0 0 0 0 Install Permeable Friction Course PTR15 1 100.0 100 100 0 0 0 1 0 0 0 0 0 0 (PFC) Segment Note: There are likely several duplicate subcategories all related to resurfacing. So gaps identified in one subcategory may in fact be covered in another subcategory. P-35
12. ROADSIDE 12.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 354 CMFs in the CMF Clearinghouse that could be categorized under Roadside. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 11. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types and crash severity levels. The following countermeasure subcategories were initially proposed but eventually deleted from the final list presented in Table 11 because there is an overlap with other subcategories: ⢠Lengthen Culvert ⢠Protect Culvert with Guardrail or Grate ⢠Remove Culvert Headwall and Delineate Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 12.2 Active/Recent Research Projects The research team identified five active NCHRP projects, one forthcoming one, and one FHWA Task Order. While it is not always clear from the project descriptions what specific CMFs will be developed, any CMFs resulting from these projects might fill some gaps related to this category: ⢠NCHRP 15-53: Roadside Barrier Designs Near Bridge Ends with Restricted Rights of Way ⢠NCHRP 15-65: Development of Safety Performance Based Guidelines for the Roadside Design Guide ⢠NCHRP 17-11(02): Development of Clear Recovery Area Guidelines ⢠NCHRP 17-82: Proposed Guidance for Fixed Objects in the Roadside Design Guide ⢠NCHRP 17-104 (FY2022): Enhancement of Roadside Design Features Safety Performance Models for the Highway Safety Manual ⢠FHWA Task Order: Evaluation of Safety Improvements, Phase X (Roadside fixed objects such as trees, utility poles, and guardrail faces) P-36
Table 11. CMFs of Interest for Roadside Number of CMFs Applicable Number of CMFs Applicable by Segment / Number of CMF Ratings by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban RS1a Install Median Barrier Segment 66 76.9 105 60 2 0 63 33 32 1 0 RS1b Install Median Barrier Intersection 1 40.0 40 40 0 0 1 1 0 0 0 RS2 Install Concrete Median Barrier 1 Segment 5 69.0 105 55 0 0 3 4 1 0 0 RS3 Install Cable Median Barrier Segment 83 71.6 135 10 2 0 27 30 13 35 5 RS4 Install Steel Median Barrier Segment 2 105.0 105 105 0 0 1 1 1 0 0 RS5 Install Outside Guardrail/Barrier Segment 73 113.8 130 45 0 2 1 26 24 23 0 RS6 Improve Guardrail/Barrier Segment 3 98.3 100 95 0 0 3 0 3 0 0 RS7 Change Barrier Type Segment 2 105.0 105 105 0 0 0 0 1 1 0 RS8 Install End Treatment Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 RS9 Change Clear Zone Width Segment 8 90.0 105 80 0 0 8 2 6 0 0 RS10 Flatten Sideslope Segment 82 84.5 115 50 0 0 82 42 38 0 2 RS11 Remove or Relocate Fixed Object Segment 3 91.7 95 85 2 0 0 2 1 0 0 RS12 Install Breakaway Supports on Poles Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 RS13 Install Breakaway Supports on Signs 2 Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 RS14 Change the Longitudinal Density of Utility Poles Segment 1 70.0 70 70 0 0 1 1 0 0 0 RS15 Change the Lateral Offset of Utility Poles Segment 1 70.0 70 70 0 0 1 1 0 0 0 RS16 Cushion Fixed Object Segment 3 105.0 105 105 0 0 0 0 1 1 1 RS17 Construct Gateway Monument Segment 2 100.0 110 90 2 0 0 2 0 0 0 RS18 Change Roadside Hazard Rating 3 Segment 1 N/A N/A N/A 0 0 1 1 0 0 0 RS19 Install Travel Information/Rest Areas Segment 2 60.0 65 55 0 0 0 2 0 0 0 RS20 Install Snow Fencing Segment 8 87.5 95 75 2 0 6 4 2 0 2 RS21 Install Truck Escape Ramp Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 RS22 Improve Horizontal Sightline Offset Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 RS23 Replace or Upgrade Barrier End Unit Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 RS24 Install Motorcycle Rub Rail under Existing W-Beam Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 RS25 Install Turnouts Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 RS26 Flatten Sideslope and Remove Guard Rail Segment 1 75.0 75 75 1 0 0 1 0 0 0 P-37
Number of CMFs Applicable Number of CMFs Applicable by Segment / Number of CMF Ratings by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban RS27 Install Guardrail around Roadside Hazards Segment 1 40.0 40 40 0 0 1 1 0 0 0 RS28a Provide Landscaping to Median Segment 2 105.0 105 105 0 2 0 2 0 0 0 RS28b Provide Landscaping to Median Intersection 3 66.7 70 60 0 0 0 1 2 0 0 RS29a Change Median Type Segment 1 105.0 105 105 0 1 0 1 0 0 0 RS29b Change Median Type Intersection 1 75.0 75 75 1 0 0 1 0 0 0 1 Related to âCable Median Barriers in Combination with Rumble Strips on Divided Roadsâ. CMFs are available in FHWA-HRT-17-070, but not yet in the Clearinghouse 2 There is a NHTSA study, albeit dated, that is not referenced in the Clearinghouse: https://trid.trb.org/view/162773 3 CMF originates in the Highway Safety Manual and could not be rated in the Clearinghouse. P-38
13. ROADWAY 13.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 1009 CMFs in the CMF Clearinghouse that could be categorized under Roadway. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 12. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types, number of lanes, and crash severity levels. The following countermeasure subcategories were initially proposed but eventually deleted from the final list presented in Table 12 because they are too generic and/or there is an overlap with other subcategories: ⢠Install Turnouts ⢠Improve Ramp Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 13.2 Active/Recent Research Projects The research team identified four active NCHRP projects, one FY2022 upcoming project, and one recently completed FHWA Task Order. While it is not always clear from the project descriptions what specific CMFs will be developed, any CMFs resulting from these projects might fill some gaps related to this category: ⢠NCHRP 15-75: Update of the Policy on Geometric Design of Highways and Streets Guidance on Acceleration/Deceleration and Stopping Sight Distance Criteria ⢠NCHRP 17-79: Safety Effects of Raising Speed Limits to 75 mph and Higher ⢠NCHRP 17-89A: HOV/HOT Freeway Crash Prediction Method for the Highway Safety Manual ⢠NCHRP 15-68: Effective Low-Noise Rumble Strips ⢠NCHRP 17-106 (FY2022): Motorist Behavior and Safety Impacts on Bicyclists from Centerline and Shoulder Rumble Strips on High-Speed Two-Lane Highways ⢠FHWA-HRT-21-013: Developing Crash Modification Factors for Bicycle Lane Additions While Reducing Lane and Shoulder Widths P-39
Table 12. CMFs of Interest for Roadway Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Number Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in of Lanes Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane RW1a Change Number of Lanes Segment 27 109.3 135 40 0 25 0 14 13 0 0 2 2 2 RW1b Change Number of Lanes Intersection 4 125.0 135 110 0 3 0 4 0 0 0 0 0 0 Add a through lane and raised RW2 Segment 7 78.6 115 30 0 5 2 5 2 0 0 7 0 0 median Convert 2-Lane Road to 4-Lane RW3 Segment 13 117.7 125 105 3 5 5 6 4 1 2 13 0 0 Divided Road RW4 Conduct Road Diet Segment 36 62.3 142 30 0 16 0 33 2 0 1 0 36 20 RW5 Change Lane Width Segment 111 88.7 130 40 0 72 31 71 32 3 5 67 52 45 Change both Lane Width and RW6 Segment 13 96.5 105 85 1 1 11 12 1 0 0 12 0 0 Shoulder Width RW7 Install Passing or Climbing Lane Segment 37 52.0 140 20 0 0 37 14 23 0 0 37 0 0 RW8a Add Two-Way Left Turn Lane Segment 28 113.6 140 75 14 4 7 21 7 0 0 26 0 0 RW8b Add Two-Way Left Turn Lane Intersection 2 85.0 95 75 2 0 0 2 0 0 0 2 2 2 RW9 Lane Restrictions - High Occupancy Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 RW10 Lane Restrictions - Truck Segment 25 81.4 130 15 0 0 0 12 13 0 0 17 4 4 RW11 Change Pavement Width Segment 9 121.1 135 90 0 0 7 5 3 0 1 7 0 0 RW12 Reallocate Pavement Width Segment 32 74.5 135 10 0 31 0 26 4 0 2 0 17 6 RW13 Widen Managed Lane Envelope Segment 3 103.3 115 90 0 3 0 2 1 0 0 0 0 0 Install Raised Pavement Markers on RW14 Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Median RW15a Provide Transverse Rumble Strips Segment 4 71.3 75 60 0 3 1 2 1 0 1 3 0 0 RW15b Provide Transverse Rumble Strips Intersection 35 99.6 125 80 1 0 33 15 9 3 8 17 0 0 RW16 Provide Center Line Rumble Strips Segment 140 94.6 150 0 0 4 133 87 41 10 2 138 0 0 Provide Rectangular Center Line RW17 Segment 4 118.8 130 105 0 0 4 3 1 0 0 4 0 0 Rumble Strips Provide Shoulder Rumble RW18 Segment 369 83.8 140 0 12 20 332 193 154 16 6 135 31 29 Strips/Stripes RW19 Provide Edge Line Rumble Stripes Segment 34 100.0 135 5 0 0 31 10 24 0 0 20 0 0 Provide Centerline and Shoulder RW20 Segment 68 102.1 140 10 0 0 67 46 11 9 2 65 3 1 Rumble Strips RW21 Improve Drainage Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 P-40
Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Number Applicable by Area Type Crash Severity CM ID Countermeasure Name Intersection CMFs in of Lanes Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane RW22 Install Glare Shields Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 RW23 Remove Curb Parking Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 RW24 Install Wildlife Detection Systems Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Change for HOV Lane Type of RW25 Segment 2 30.0 30 30 0 0 0 1 0 1 0 0 0 0 Access (e.g., Continuous, Limited) Reduce Lane Width at Intersection RW26 using Rumble Strips and Painted Intersection 4 10.0 10 10 0 0 4 3 1 0 0 0 0 4 Median RW27 Provide Truck Climbing Lane Segment 2 107.5 115 100 0 0 0 2 0 0 0 0 0 0 P-41
14. RAILROAD CROSSING 14.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 11 CMFs in the CMF Clearinghouse that could be categorized under Railroad Crossing. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 13. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to crash severity levels. The following countermeasure subcategories were initially proposed but eventually deleted from the final list presented in Table 13 because there is an overlap with other subcategories: ⢠Railroad Grade Crossing Electronics ⢠Install Median Barrier Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 14.2 Active/Recent Research Projects The research team did not find any ongoing projects from NCHRP or FHWA that would likely produce more CMFs related to this category. P-42
Table 13. CMFs of Interest for Railroad Crossing Number of CMFs Applicable by Segment / Number of CMF Ratings CM Crash Severity Countermeasure Name Intersection CMFs in ID Related CMF-CH Mean Max Min KABCO KABC KAB PDO RR1 Close, Eliminate, or Separate Railroad Grade Crossing RR-Xing 0 N/A N/A N/A 0 0 0 0 RR2 Traffic Control at Railroad Grade Crossing RR-Xing 2 115.0 115 115 2 0 0 0 RR3 Modify Railroad Crossing Alignment and Surface RR-Xing 0 N/A N/A N/A 0 0 0 0 RR4 Install Automatic Railroad Gates RR-Xing 2 105.0 105 105 2 0 0 0 RR5 Install Signs and Crossbucks RR-Xing 6 115.0 130 105 6 0 0 0 RR6 Install Flashing Lights RR-Xing 0 N/A N/A N/A 0 0 0 0 RR7 Install Flashing Beacons RR-Xing 0 N/A N/A N/A 0 0 0 0 RR8 Install Warning Bells RR-Xing 0 N/A N/A N/A 0 0 0 0 RR9 Install Pavement Markings RR-Xing 0 N/A N/A N/A 0 0 0 0 RR10 Install Delineators RR-Xing 0 N/A N/A N/A 0 0 0 0 RR11 Install Safety Lighting RR-Xing 0 N/A N/A N/A 0 0 0 0 RR12 Install Flashing Lights and Sound Signals RR-Xing 1 105.0 105 105 1 0 0 0 1 There are 5 more CMFs from one study in the Clearinghouse for installing gates at crossings with signs â âAutomaticâ, though implied, is not in the countermeasure name. 2 There are 5 related CMFs in the Clearinghouse identified as âupgrade signs to flashing lightsâ. Also potentially related is âInstall Flashing Lights and Sound Signalsâ, which is listed below. P-43
15. HIGHWAY SHOULDERS 15.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 930 CMFs in the CMF Clearinghouse that could be categorized under Highway Shoulders. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 14. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types, number of lanes and crash severity levels. Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 15.2 Active/Recent Research Projects The research team identified two active NCHRP projects. While it is not clear from the project descriptions what specific CMFs will be developed, any CMFs resulting from these projects might fill some gaps related to this category: ⢠NCHRP 17-89: Safety Performance of Part-Time Shoulder Use on Freeways ⢠NCHRP 15-68: Effective Low-Noise Rumble Strips P-44
Table 14. CMFs of Interest for Shoulders Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by CM Applicable by Area Type Crash Severity Countermeasure Name Intersection CMFs in Number of Lanes ID Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane SH1a Change Shoulder Width Segment 349 101.0 130 0 0 116 212 140 108 51 50 130 122 83 SH1b Change Shoulder Width Intersection 5 93.0 110 75 1 0 3 5 0 0 0 4 1 1 SH2 Change Shoulder Width (Unpaved) Segment 43 92.1 105 70 0 0 43 22 17 4 0 43 0 0 SH3 Install Safety Edge Treatment Segment 131 128.1 147 80 0 0 131 66 30 6 29 119 0 0 Install Safety Edge Treatment and SH4 Segment 4 88.8 95 80 4 0 0 2 2 0 0 0 0 0 Widen Lanes Provide or Convert Unpaved SH5 Segment 7 92.9 100 80 0 0 7 5 2 0 0 7 0 0 Shoulder to Composite Shoulder Convert Shoulder Type and SH6 Segment 42 99.4 105 70 0 0 42 28 14 0 0 42 0 0 Change Shoulder Width SH7 Install Curb and Gutter Segment 1 110.0 110 110 0 1 0 1 0 0 0 0 1 0 Covert Paved Shoulder to Curb SH8 Segment 1 105.0 105 105 0 1 0 1 0 0 0 0 0 1 and Gutter SH9 Install Barrier Curb on Road Edge Segment 3 10.0 10 10 0 3 0 3 0 0 0 0 0 0 SH10 Convert to Gravel Shoulder Segment 2 82.5 95 70 0 1 0 1 1 0 0 1 1 1 SH11 Convert to Other Shoulder Type Segment 1 80.0 80 80 0 1 0 1 0 0 0 1 0 0 SH12 Convert to Paved Shoulder Segment 152 84.0 115 0 4 81 63 17 50 43 42 82 45 41 SH13 Convert to Turf Shoulder Segment 7 N/A N/A N/A 0 0 7 7 0 0 0 7 0 0 Install Alternative Audible Lane SH14 Segment 4 90.0 100 75 0 0 4 1 2 0 1 4 0 0 Departure Warning Treatments SH15 Repave deterriorated shoulder Segment 90 123.6 130 110 0 45 45 0 30 30 30 30 30 30 SH16 Provide 2ft Paved Shoulder Segment 12 110.0 115 105 0 0 12 6 6 0 0 4 0 0 Provide Paved Shoulder and SH17 Segment 5 80.0 105 5 4 0 0 3 2 0 0 1 0 0 Shoulder Rumble Strips Widen Shoulder and Install SH18 Segment 20 65.5 130 10 0 0 18 11 9 0 0 0 18 18 Shoulder Rumble Strips Install a Combination of Shoulder Rumble Stripes, Shoulder SH19 Segment 58 84.3 95 65 0 0 58 22 18 12 6 58 0 0 Widening and Resurface Pavement P-45
16. HIGHWAY SIGNS 16.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 214 CMFs in the CMF Clearinghouse that could be categorized under Highway Signs. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 15. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types, number of lanes, and crash severity levels. The following countermeasure subcategories were initially proposed but eventually deleted from the final list presented in Table 15 because they are too generic and/or there is an overlap with other subcategories: ⢠Install Speed Signing ⢠Install Signs, Flashers, and Markings ⢠Install A Solar Powered Flasher on An Existing Curve Warning Sign with Advisory Speed Plate ⢠Actuated "Prepare to Stop When Flashing" Signs In Advance Of Intersection With Sight Distance Issues Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 16.2 Active/Recent Research Projects The research team did not find any ongoing projects from NCHRP or FHWA that would likely produce more CMFs related to this category. P-46
Table 15. CMFs of Interest for Signs Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Number CM Applicable by Area Type Crash Severity Countermeasure Name Intersection CMFs in of Lanes ID Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane S1 Install Signs Segment 2 105.0 105 105 0 2 0 0 1 0 1 0 0 0 S2 Install STOP Signs Intersection 6 82.5 120 60 1 3 0 5 1 0 0 2 1 1 Install Advance Curve/Speed S3 Segment 4 90.0 105 75 0 0 0 0 2 0 2 0 0 0 Warning Sign S4 Install Chevron Signs Segment 18 98.3 140 20 1 1 7 14 3 0 1 7 9 0 Replace Larger Stop-sign and Add S5 Intersection 1 30.0 30 30 0 1 0 1 0 0 0 0 0 0 Centerline and Stop-bar S6a Increase Retroreflectivity of Sign(s) Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 S6b Increase Retroreflectivity of Sign(s) Intersection 36 112.5 130 90 26 4 6 33 3 0 0 0 0 0 S7a Upgrade to Flashing LED Signs Segment 5 117.0 130 105 0 0 0 5 0 0 0 0 0 0 S7b Upgrade to Flashing LED Signs Intersection 2 110.0 130 90 0 0 0 2 0 0 0 0 0 0 Install Advance Signal Warning S8 Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Signs S9 Install Advance Street Name Signs Intersection 5 102.0 110 100 5 0 0 4 1 0 0 0 0 0 S10 Install Yield Signs Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 S11 Install Lane Use Signs Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 S12 Improve Sign Visibility Segment 5 146.4 150 145 0 0 5 4 1 0 0 5 0 0 S13 Install Oversized Signs Segment 7 110.0 130 100 0 0 0 6 1 0 0 0 0 0 Install "Intersection Conflict Warning S14 Intersection 45 121.2 150 95 0 0 45 30 15 0 0 33 18 6 Systems" (ICWS) System S15 Install Sequential Dynamic Chevrons Segment 2 107.5 110 105 0 0 2 1 1 0 0 2 0 0 Install Advance Curve Warning S16 Flashers (Curve Warning Signs Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Exist) Install a Detection Warning System S17 with CCTV's, Warning Signs with Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Flashers, and DMS's Reduce Regulatory Speed Limit in S18 Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Curve Actuated Advanced Flasher at S19 Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Official Use Crossover P-47
Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Number CM Applicable by Area Type Crash Severity Countermeasure Name Intersection CMFs in of Lanes ID Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane Install Static Signs and Flashers S20 "Truck Speed too Fast when Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Flashing" Provide a Mandatory Motorcycle Pull S21 Off Area with Roadway Informational Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 Signing Install Combination of Chevron, S22 Curve Warning and Flashing Segment 63 113.6 130 95 1 0 0 49 7 0 7 0 63 0 Beacons Install Yield/Stop Markings and S23 Segment 3 108.3 115 105 0 3 0 3 0 0 0 3 3 3 Signs S24a Install Advance Warning Sign Segment 2 47.5 85 10 0 0 2 2 0 0 0 1 0 0 S24b Install Advance Warning Sign Intersection 1 30.0 30 30 0 1 0 1 0 0 0 0 0 0 S25 Install Double Stop Signs Intersection 1 10.0 10 10 0 1 0 1 0 0 0 0 0 0 S26 Install Drowsy Driving Signs Segment 2 55.0 65 45 0 0 0 2 0 0 0 0 0 0 Install Improved Advance Junction S27a Segment 1 10.0 10 10 0 0 0 1 0 0 0 0 0 0 Guidance Signs Install Improved Advance Junction S27b Intersection 2 15.0 15 15 0 0 2 2 0 0 0 0 0 0 Guidance Signs Install Active Close-following S28 Segment 1 75.0 75 75 0 0 0 1 0 0 0 0 0 0 Warning Signs P-48
17. BRIDGES AND STRUCTURES 17.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 26 CMFs in the CMF Clearinghouse that could be categorized under Bridges and Structures. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 16. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to crash severity levels. The following countermeasure subcategories were initially proposed but eventually deleted from the final list presented in Table 16 because they are too generic and/or there is an overlap with other subcategories: ⢠Replace Bridge ⢠Build New Bridge ⢠Build Structure ⢠Remove Bridge Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 17.2 Active/Recent Research Projects The research team identified one active NCHRP project. While it is not clear from the project description what specific CMFs will be developed, any CMFs resulting from this project might fill some gaps related to this category: ⢠NCHRP 08-139: Guide for Preventing and Mitigating the Risk of Bridge and Tunnel Strikes by Motor Vehicles P-49
Table 16. CMFs of Interest for Bridges and Structures Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings CM Applicable by Area Type Crash Severity Countermeasure Name Intersection CMFs in ID Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban ST1 Remove Mainline Barrier Toll Plazas on Highways Segment 3 80.0 80 80 0 0 0 1 1 0 1 ST2 Improve Drainage Structures Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ST3 Grooving Bridge Pavement Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ST4 Install Frost/Ice Detectors on Bridge Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ST5a Install Fixed Automated Spray Technology (FAST) Segment 16 60.9 80 55 0 7 9 16 0 0 0 ST5b Install Fixed Automated Spray Technology (FAST) Intersection 3 56.7 60 55 3 0 0 3 0 0 0 ST6 Change Bridge Width Segment 1 115.0 115 115 0 0 0 1 0 0 0 ST7 Replace Bridge Guardrail Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ST8 Install Barrier on Bridge Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ST9 Upgrade Bridge Rail Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ST10 Provide Separation between Pedestrians and Traffic Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ST11 Install Overhead Sign Truss Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 ST12 Install anti-icing Pavement Overlay System Segment 3 23.3 30 10 0 0 0 1 1 0 1 P-50
18. HIGHWAY WORK ZONES 18.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 81 CMFs in the CMF Clearinghouse that could be categorized under Highway Work Zones. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 17. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types and crash severity levels. Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 18.2 Active/Recent Research Projects The research team identified two active NCHRP projects. While it is not clear from the project descriptions what specific CMFs will be developed, any CMFs resulting from these projects might fill some gaps related to this category: ⢠NCHRP 03-134 Determination of Encroachment Conditions in Work Zones ⢠NCHRP 03-132 Guidance for Safe and Effective Temporary Traffic Control for Mobile Operations on Two- Lane Two-Way Roadways P-51
Table 17. CMFs of Interest for Work Zone Number of CMFs Applicable Number of CMFs Applicable by Crash Segment / Number of CMF Ratings by Area Type Severity CM ID Countermeasure Name Intersection CMFs in Urban Related CMF-CH Mean Max Min All Rural KABCO KABC KAB PDO /Suburban W1 Modify Work Zone Duration Segment 1 N/A N/A N/A 1 0 0 1 0 0 0 W2 Modify Work Zone Length Segment 1 N/A N/A N/A 1 0 0 1 0 0 0 W3 Close lanes in Work Zone Segment 53 125.2 140 20 1 0 0 21 16 0 16 W4 Change Shoulder Width Inside Work Zone Segment 3 135.0 135 135 0 2 0 3 0 0 0 W5 Implement Two-Way Operation in Work Zone Segment 1 10.0 10 10 0 0 0 1 0 0 0 W6 Inactive Work Zone with no Lane Closure Segment 24 134.6 140 115 0 0 0 8 8 0 8 P-52
19. OTHER COUNTERMEASURES 19.1 Existing CMFs in the CMF Clearinghouse The research team identified a total of 370 CMFs in the CMF Clearinghouse that could be categorized under Other Countermeasures. After grouping them into appropriate subcategories of countermeasures, calculating the rating scores and counting the numbers of CMFs, the results are summarized and presented in Table 18. The Mean, Max and Min values of CMFs ratings represent the average, highest, and lowest rating scores, respectively for all CMFs available in each subcategory of countermeasures. The table also includes the number of CMFs in each subcategory that are applicable to different area types, number of lanes, and crash severity levels. Identified gaps are color-coded in the tables as follows: shaded rows indicate countermeasure subcategories for which no rated CMFs are available. (In a few cases the Highway Safety Manual is the source of the Clearinghouse CMF, and it could not be rated.) shaded rows indicate countermeasure subcategories for which CMFs are available, but the maximum rating suggests low quality (<75). shaded rows indicate countermeasure subcategories for which 5 or more CMFs (with a maximum mating of 75 or more) are available but for which there are gaps in area type, severity type, etc. For the last color code, and for the remaining subcategories with no shading, the red font color for the number of CMFs (i.e., 0) indicates the gap(s) identified. It should be emphasized that the gaps identified here will need confirmation as such before research to fill the gap is considered. 19.2 Active/Recent Research Projects The research team identified two active NCHRP projects and one recently completed FHWA Task Order. While it is not always clear from the project descriptions what specific CMFs will be developed, any CMFs resulting from these projects might fill some gaps related to this category: ⢠FHWA-HRT-21-053: Developing Crash Modification Factors for Variable Speed Limit. ⢠NCHRP 06-18 Guide for Snow and Ice Control Operations ⢠NCHRP 17-92 Developing Safety Performance Functions for Rural Two-Lane Highways that Incorporate Speed Measures P-53
Table 18. CMFs of Interest for Other Countermeasures Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Area Applicable by CM Crash Severity Countermeasure Name Intersection CMFs in Type Number of Lanes ID Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane O1 Change Unrestricted Left Turn Hours Segment 6 105.0 105 105 0 6 0 6 0 0 0 0 0 0 O2 Prohibit On-Street Parking Segment 6 62.5 105 30 0 6 0 1 3 0 2 0 0 0 Change Unrestricted Parking Hours O3 Segment 4 105.0 105 105 0 4 0 4 0 0 0 0 0 0 during Rush Hour from X to Y Hours Implement Time-Limited Parking O4 Segment 2 105.0 105 105 0 2 0 2 0 0 0 0 0 0 Restrictions Convert Angle Parking to Parallel O5 Segment 8 36.3 105 0 0 8 0 6 2 0 0 0 0 0 Parking Convert Parallel Parking to Angle O6 Segment 2 10.0 10 10 0 2 0 2 0 0 0 0 0 0 Parking O7 Convert Free to Regulated Parking Segment 2 92.5 105 80 0 2 0 0 1 0 1 0 0 0 O8a Change Posted Speed Segment 116 111.0 150 40 9 19 71 70 23 18 5 23 8 13 O8b Change Posted Speed Intersection 67 110.1 140 50 0 6 61 42 11 14 0 62 0 4 O9 Change Operating Speed Segment 14 102.9 105 90 12 0 2 0 6 4 4 2 0 0 O10a Install Speed Humps Segment 3 75.0 75 75 0 3 0 0 3 0 0 3 0 0 O10b Install Speed Humps Intersection 1 60.0 60 60 0 1 0 1 0 0 0 0 0 0 Speed Management/Implement Traffic O11 Segment 4 75.0 75 75 0 4 0 1 2 0 1 4 0 0 Calming O12 Implement Area-Wide Traffic Calming Segment 6 75.0 75 75 0 6 0 0 3 0 3 4 2 2 O13a Change Transit Stop Presence/Location Segment 2 105.0 105 105 0 2 0 0 0 2 0 0 0 0 O13b Change Transit Stop Presence/Location Intersection 2 82.5 85 80 0 1 0 2 0 0 0 0 0 0 O14 Install Transit Lane Priority Segment 1 105.0 105 105 0 0 0 1 0 0 0 0 0 0 O15 Install Transit Signal Priority Intersection 6 113.3 120 100 0 4 0 6 0 0 0 0 0 0 O16 Change Right of Way Segment 0 N/A N/A N/A 0 0 0 0 0 0 0 0 0 0 O17 Install supplemental rest areas Segment 6 110.0 110 110 0 0 0 0 6 0 0 0 3 5 Convert Type of Toll Booth/Toll O18 Segment 21 98.1 110 50 5 0 0 13 4 0 4 0 0 0 Collection O19 Use Salt for De-icing Segment 4 75.0 75 75 4 0 0 0 2 0 2 0 0 0 Implement Black Spot Treatment O20 Intersection 13 81.2 85 55 11 2 0 0 12 1 0 1 1 0 Program P-54
Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Area Applicable by CM Crash Severity Countermeasure Name Intersection CMFs in Type Number of Lanes ID Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane Implement Safety Routes to School O21 Segment 7 39.3 50 25 0 0 0 5 1 1 0 0 0 0 Program Implement Differential Speed Limit O22 Segment 1 105.0 105 105 0 0 1 1 0 0 0 0 0 0 (Truck) O23 Install Icy Curve Warning System Segment 1 85.0 85 85 0 0 1 1 0 0 0 1 1 1 Install Light-Reflecting Devices (Animal O24 Segment 1 95.0 95 95 0 0 0 1 0 0 0 0 0 0 Collision) Implement home zone design in O25 Segment 1 25.0 25 25 0 0 0 1 0 0 0 0 0 0 residential neighborhoods Install Platform Tram/Streetcar Stops O26 Segment 8 65.6 105 0 0 8 0 3 3 2 0 0 0 0 (Pedestrian Safety) O27 Install Shared Path Segment 1 50.0 50 50 0 1 0 1 0 0 0 0 0 1 O28 Change Winter Maintenance Standard Segment 2 105.0 105 105 2 0 0 0 1 0 1 0 0 0 O29 Implement Section Control Segment 8 75.0 85 65 0 0 8 0 4 4 0 2 0 0 O30 Control Snow, Slush, and Ice Segment 3 75.0 75 75 3 0 0 3 0 0 0 0 0 0 O31 Change Public Transit Type Intersection 6 115.0 115 115 0 6 0 6 0 0 0 0 0 0 Presence of Grass Roadside (Animal O32 Segment 1 85.0 85 85 0 1 0 1 0 0 0 1 1 1 Collision) Presence of Near-side/Far-side Transit O33 Intersection 3 115.0 115 115 0 3 0 3 0 0 0 0 0 0 Stops O34 Presence of Transit Service Intersection 2 115.0 115 115 0 2 0 2 0 0 0 0 0 0 Presence of Parking Entrance (Bicyclist O35 Intersection 1 85.0 85 85 0 1 0 1 0 0 0 0 0 0 Safety) Presence of 2-lane versus more than 2- O36 Segment 1 95.0 95 95 0 1 0 1 0 0 0 1 1 1 lane roadway (Animal Collision) Presence of Horizontal Curve and O37 Intersection/Driveway Within Sight Segment 2 92.5 105 80 0 0 2 1 1 0 0 2 0 0 Restricted Area O38 Mark Parking Stalls Segment 2 105.0 105 105 0 2 0 2 0 0 0 0 0 0 Media Coverage of Automated Speed O39 Segment 3 60.0 60 60 0 0 0 1 1 0 1 0 0 0 Enforcement Cameras Treat Median for Pedestrian and O40 Segment 4 81.3 100 60 0 4 0 2 1 1 0 0 0 0 Bicyclist Safety Change Type of Land use (e.g., O41 Segment 5 113.0 125 105 0 5 0 2 0 3 0 0 0 0 Commercial vs Residential) P-55
Number of CMFs Number of CMFs Number of CMFs Applicable by Segment / Number of CMF Ratings Applicable by Area Applicable by CM Crash Severity Countermeasure Name Intersection CMFs in Type Number of Lanes ID Related CMF-CH Urban 2- 4- Mean Max Min All Rural KABCO KABC KAB PDO Other /Suburban Lane Lane Change Total Park Area (Pedestrian O42 Segment 1 105.0 105 105 0 1 0 0 0 1 0 0 0 0 Safety) O43 Allow Parking on Both Sides of Road Segment 2 62.5 75 50 0 2 0 2 0 0 0 1 0 1 Change Proportion of Roadway Type O44 Segment 8 105.0 105 105 0 8 0 0 0 8 0 0 0 0 (Planning level) P-56
