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TCRP Web-Only Document 53 46 CHAPTER 4: MODELING/SIMULATION OF LIGHT RAIL OPERATING CONDITIONS: NORTH FIRST STREET FROM EAST BROKAW ROAD TO TRIMBLE ROAD INTRODUCTION Objectives: The objective of this study was to develop a micro-simulation model for the Light Rail corridor on North Frist St. from East Brokaw Road to Trimble Road in San Jose, California in order to analyze the simulated intersection safety under existing and suggested conditions (increasing LRV operating speed from 35 mph to 45 mph). Using the FHWAâs newly developed SSAM model (Surrogate Safety Assessment Model), it would be feasible to compare the frequency of various types of conflicts (rear-end, angle and lane change) among the base condition and the various alternatives. The micro-simulation approach was determined by the panel to be a feasible alternative to conducting a field evaluation, necessitated by the City of San Joseâs decision to not participate in a field test. Study Area: The study area roadway network is located in San Jose, California, and includes an approximate 1.3 mile section of North First St. and five signalized intersections along the corridor. The Light Rail track runs in the median between the northbound and southbound travel lanes. There are no gates at the at-grade light rail crossings on North First St.. There are two light rail stops in the northbound direction and three stops in the southbound direction within the study limits. The light rail service, operated by the Santa Clara Valley Transportation Authority (VTA) has two lines that utilize the stops within the study limits of the model: The Alum Rock- Santa Teresa and the Mountain View-Winchester lines. MODELING METHODOLOGY AND ANALYSIS TOOLS The modeling effort comprised of three analysis tools: Synchroâ¢, VISSIM⢠and SSAM. Each model/analysis tool is discussed briefly below. SYNCHRO⢠Synchro⢠(developed by Trafficware, Inc.) is a macroscopic analysis tool capable of modeling signalized and unsignalized intersections. Synchro⢠is commonly used for intersection capacity and level-of-service analysis and signal timing optimization. Synchro⢠has the ability to compute optimum timings for intersection offsets, cycle lengths, phase splits, and phase sequence. Synchro⢠can display time-space diagrams that illustrate vehicle progression through a network. Since Synchro⢠performs its analysis at a platoon level instead of an individual vehicle level, it is categorized as a macroscopic simulation model. Synchro⢠version 7 was used to code the existing and alternative scenario models, in order to optimize the signal timing for all tested scenarios. VISSIM⢠VISSIM⢠is a time-step and behavior-based microscopic traffic simulation software. It is characterized as microscopic simulation software because of its ability to model and analyze each entity of the network at an individual vehicle level. VISSIM⢠is capable of simulating multiple modes of traffic including cars, heavy vehicles, high-occupancy vehicles, bus transit, light rail, heavy rail, rapid transit, cyclists, and pedestrians, for urban as well as rural conditions.
TCRP Web-Only Document 53 47 The VISSIM⢠model consists internally of two distinct components: the traffic simulator and the signal state generator. These components are constantly communicating detector calls and signal status to each other through an interface. The traffic simulator is a microscopic traffic flow simulation model including car following, lane changing, and gap acceptance logic. The signal state generator is signal-control software that polls detector information from the traffic simulator on a discrete time-step basis (1/10 s). It then determines the signal status for the following time-step and returns this information to the traffic simulator. This interaction is the driving force behind modeling a signalized intersection. VISSIM⢠version 5.30 release was utilized in this project to code the alternative scenarios and collect the vehicle trajectory data. SSAM SSAM, a model developed by the Federal Highway Administration, combines micro-simulation and automated conflict analysis to analyze the frequency and character of narrowly averted vehicle-to-vehicle collisions (conflicts) to compute surrogate measures of the safety of traffic facilities. SSAM determines and quantifies three types of conflicts: crossing (angle), lane changing, and rear end. For the purpose of this study, SSAM is used to determine the change in the frequency of conflicts among the various tested scenarios and the existing condition. MODEL DEVELOPMENT Model Geometry The VISSIM model of existing conditions was coded using scaled aerial images of the study network. The lane geometry was confirmed with provided lane configuration diagrams at key locations. The light rail tracks were modeled as one continuous track in each direction with two stops in the northbound direction and three stops in the southbound direction. Figure 14 illustrates the VISSIM network model created for the study. Speed Data For purposes of the model, speed distributions were developed using best engineering judgment based on field observations and the posted speed limit along North First St. and the adjacent roads. The posted speed limit along North First St. is 45mph throughout the study network. A speed distribution curve for cars was developed with a desired speed ranging from 35 mph to 50 mph with an 85th percentile speed of 45 mph. Trucks and buses were assigned a speed distribution ranging from 36 to 42 mph. Other desired speed distributions were created for intersecting roadways and multiple types of turning movements. The speed distribution for light rail vehicles was based on the 35 mph speed limit currently imposed on Light Rail Vehicles
TCRP Web-Only Document 53 48 Figure 14. VISSIM Network Model N First Street at Trimble Rd N First Street at Component N First Street at Charcot Ave N First Street at Karina Ct N First Street at   E Brokaw Rd Northbound LRT Stop #1 Northbound LRT Stop #2 Southbound LRT Stop #1 Southbound LRT Stop #2 Southbound LRT Stop #3Â
TCRP Web-Only Document 53 49 crossing ungated intersections. A linear distribution was assigned, which ranged from 34.5 to 35.5 mph. The deceleration and acceleration rates for the light rail vehicles were estimated in the field by timing and measuring the distance at which a train began to decelerate or accelerate to the point at which it stopped or reached its desired speed, respectively. Acceleration rates were calculated and modeled at 2.75 mph/s (4.03 ft/s2) while the deceleration rates were 3.0 mph/s (4.40 ft/s2). In order to analyze and report safety performance measures, pedestrian and bicycle speeds were modeled based on field video observations, while taking into consideration the guidelines outlined in the 2009 MUTCD. A speed distribution of 3.5 ft/s to 4.25 ft/s was assigned to pedestrians, while bicycles were assigned a desired speed between 9 mph and 15 mph. Transit Signal Priority The Light Rail operation within the study network runs parallel to the northbound and southbound automotive traffic. Detectors are placed along the track at various points in advance of and following an intersection. The signal controllers communicate with the detectors and attempt to provide priority for the Light Rail Vehicle approaching by applying the following methods: ï· Shortening phases not on the mainline so that the through phases which run in conjunction with the Light Rail signals can be called at an earlier time than would be in standard operation ï· Extending the through phases which run in conjunction with the Light Rail so that the Light Rail signal stays green until the Light Rail Vehicle clears the intersection ï· Adjusting the sequence in which the phases are called so that left turns which cross the Light Rail track lag behind the through phases rather than lead before them, as is the case in standard operation. Balanced Volume Network and Vehicle Routing A balanced volume network was developed for both the AM and PM peak periods, based on traffic counts taken in 2009 at the intersections of North First St. and East Brokaw Road, Charcot Avenue, and Trimble Road. These counts separated automobiles, bicycles, and pedestrians. Supplemental count data was provided by the City of San Jose at the intersection of North First St. and Karina Court and Component Drive. For the purposes of the model, the access points along the network into and out of parking lots and businesses were deemed inconsequential in the relationship between light rail operation and overall safety in the network. However, there were midblock access points to corporate office buildings (eBay, Yahoo and several other large IT companies) with as many as 1,000 parking spaces in the parking lot which account for imbalances between intersections. As such, the volume network was balanced so that there was no more than a 10% difference (rather than 0%) between the traffic count volumes and the network volumes. Based on the count data, the peak hours modeled were 8:00AM â 9:00AM and 5:00PM â 6:00PM. Figure 15 shows the volume balanced network. Routing decision points were placed at the origin links and destination links to define the vehicle routing. These routes are static in this model, meaning vehicles are routed from a starting point to a defined destination point using a static percentage for each destination. In order to allow for
TCRP Web-Only Document 53 50 122 913 130 39 800 261 118 1018 122 222 425 69 22 1011 44 48 12 123 14 22 29 21 597 26 527 758 93 37 593 107 203 216 131 383 62 81 8 1025 8 31 0 147 600 256 255 930 224 186 918 463 314 840 60 53 330 295 23 303 61 43 958 305 194 701 140 238 919 153 35 568 70 30 36 43 3 15 3 34 1158 82 192 322 39 55 178 61 495 519 117 768 113 8 13 375 12 5 0 354 1089 18 120 231 85 385 1072 329 542 672 83 106 660 309 PM Peak AM Peak adequate lane changing distance, the routing decisions were placed according to the observed driver behavior in the model, and adjusted so that vehicles had adequate time to make the decision to change lanes to reach their desired destination. Because origin-destination data was not obtained, as it is not crucial to the purpose of this study, routing decisions were placed following each intersection, so that all of the source links feed the destination links proportionately. Figure 15. Volume Balanced Networks
TCRP Web-Only Document 53 51 Vehicle Types and Compositions Based on the available data and observations recorded and made in the field, a system wide composition was assigned to all input links which included 96% Cars, 3% Trucks, and 1% Buses. Independent bicycle volumes were assigned, as were pedestrian volumes at each intersection. The input composition for the Light Rail tracks reflects the peak demand on the system. As such, all of the light rail vehicles entering the network are composed of three cars attached at a total length of approximately 265 feet. Each car is modeled to reflect the critical dimensions of the Kinki Sharyo LRV in use by the Santa Clara VTA which includes length, center pivot distance, and wheelbase. Dwell Time and Arrival Times at Light Rail Stations In order to calculate and assign dwell times to the transit stations in the corridor, stop time data was obtained from a 2009 study as part of the Regional Signal Timing Program (RSTP), which measured the dwell times at each stop along the Alum Rock-Santa Teresa Line. Due to the variability in dwell times between individual runs and from station to station, an overall empirical distribution was developed to be assigned to all stations in the study network. In this process, outliers were eliminated so that the model would not reflect a long stop time that may be attributed to an operator waiting at a station for the light rail signal to change to green. Outliers on the lower end were also eliminated, as this may reflect a stop with no passengers boarding or alighting. The empirical distribution developed ranges from 5 seconds to 55 seconds, with an 85th percentile stop time of 29 seconds. The arrival times coded in the VISSIM model are based on the observed headways in the field. From the field data, it was observed that the light rail vehicles operated with headways between seven and seven and a half minutes. To reflect this variability in arrival times, the entry times of the vehicles into the network were developed using a random number generator. The headway between each train was assigned to be a random time between seven minutes and seven minutes and thirty seconds. Model Calibration and Validation Calibration of a model can be explained as the adjustment of the model parameters so that the model produces a simulation with behavior and output performance measures consistent with existing field operation. Calibration requires development of a base conditions model, comparison with field traffic conditions, and adjustment of model parameters so that the base computer model accurately resembles field conditions. The goal of model calibration is to improve the modelâs ability to simulate existing conditions, and thus increase the analystâs confidence in the results of the alternative condition models. In calibrating the model in this study, the main parameter involved was throughput. The network was calibrated so that the intersections at the beginning and end of the network had throughput within five percent of the target volumes developed in the volume balanced network. In order to validate the model, visual observations were made on intersection operation, transit priority behavior, and intersection queues, and compared to video observations taken during peak hours at multiple intersections.
TCRP Web-Only Document 53 52 BASE CONDITION ANALYSIS Following the development of the base condition model in VISSIM, trajectory files were output for processing in SSAM. Five 5-hour simulations were run per peak period, with peak hour volumes input for each of the five hours. The headway for train is approximately 7 to 7.5 minutes in each direction, which amounts to simulating a total of 200 trains in each direction at each intersection. Following the processing of the output trajectory files using SSAM, the conflicts were identified and sorted by type and intersection. A conflict, as defined in the Surrogate Safety Assessment Model and Validation Final Report as an observable situation in which two or more road users approach each other in time and space to such an extent that there is risk of collision if their movements remain unchanged. It is important to note that a conflict does not mean a collision. For example, rear-end conflicts are common in situations where a following driver reacts to a leading driver applying their brakes. If the following driver were to continue their course and speed, a collision would occur. The default/recommended parameters in SSAM were used for the analysis, among which includes a maximum 1.5 second TTC (Time to Collision) value. The TTC value of 1.5 seconds can be explained as follows: If two interacting vehicles were on a path such that if neither changed their desired speed or course in 1.5 seconds or less, they would collide; this is logged as a conflict. This study specifically focused on the crossing conflicts (angle and left-turn conflicts) that involved light rail vehicles. The results of the SSAM analysis for the base conditions are shown in Figure 16 and Figure 17. The intersection at North First St. and East Brokaw Road shows the greatest number of total conflicts (an average of 481 and 588 conflicts during each 5-hour simulation period) for both AM and PM peak periods, respectively. The majority of these conflicts are rear-end or lane change types. The intersections of North First St., East Brokaw Road and Trimble Road showed/simulated the greatest number of non-LRV crossing conflicts during the AM peak and PM peaks periods, respectively; an average of 2 to 3 crossing conflicts for each 5-hour simulation period. However, none of those conflicts involved a light rail vehicle. The findings of the simulation were not unusual considering that between May 2006 and May 2009 an average of one or two light rail vehicle accidents was reported each year at the most critical intersection of the study, North First St. at Brokaw Road. The findings related to the non-LRV conflicts during the peak periods are also confirmed by the field data, which showed the intersection of North First St. and East Brokaw Road to be the intersection with the greatest number of observed conflicts. The challenge in this modeling task is that the number of conflicts that could be observed under the various alternatives may or may not show any significant increase or change in the LRV- related conflicts. This is in part because no LRV conflicts were reported in the simulation for any of the existing conflicts scenarios.
TCRP Web-Only Document 53 53 Crossing Rear End Lane Change N First St at E Brokaw 2407 11 2287 109 N First St at Karina Ct 523 0 486 37 N First St at Charcot Ave 1337 3 1295 39 N First St at Component Dr 1020 8 986 26 N First St at Trimble Rd 1824 4 1742 78 Type of Conflict Intersection Total Conflicts AM Peak Period Conflicts (5 simulations of 5 hours each) Crossing Rear End Lane Change 1 432 5 409 18 2 499 1 482 16 3 486 4 458 24 4 490 1 470 19 5 500 0 468 32 Total 2407 11 2287 109 Average 481 2 457 22 St. Dev 28.2 2.2 28.4 6.4 Coefficient of Variation 0.06 0.99 0.06 0.29 1 79 0 75 4 2 100 0 94 6 3 106 0 95 11 4 123 0 117 6 5 115 0 105 10 Total 523 0 486 37 Average 105 0 97 7 St. Dev 16.8 0.0 15.5 3.0 Coefficient of Variation 0.16 0.00 0.16 0.40 1 247 1 238 8 2 286 1 278 7 3 259 1 250 8 4 274 0 264 10 5 271 0 265 6 Total 1337 3 1295 39 Average 267 1 259 8 St. Dev 14.9 0.5 15.4 1.5 Coefficient of Variation 0.06 0.91 0.06 0.19 1 190 1 187 2 2 219 2 211 6 3 202 1 197 4 4 204 2 199 3 5 205 2 192 11 Total 1020 8 986 26 Average 204 2 197 5 St. Dev 10.3 0.5 9.0 3.6 Coefficient of Variation 0.05 0.34 0.05 0.69 1 359 0 337 22 2 362 2 346 14 3 372 0 362 10 4 372 2 354 16 5 359 0 343 16 Total 1824 4 1742 78 Average 365 1 348 16 St. Dev 6.7 1.1 9.8 4.3 Coefficient of Variation 0.02 1.37 0.03 0.28 N First St at Trimble Rd N First St at Component Dr N First St at Charcot Ave N First St at Karina Ct N First St at E Brokaw AM Peak Period Conflicts (5 hour simulation period) Intersection Total Conflicts Type of Conflict Simulation # Figure 16. Summary of AM Peak Hour Conflicts Note:  No light rail conflicts were observed or recorded.Â
TCRP Web-Only Document 53 54 Crossing Rear End Lane Change N First St at E Brokaw 2942 6 2831 105 N First St at Karina Ct 1235 4 1147 84 N First St at Charcot Ave 1465 4 1365 96 N First St at Component Dr 465 4 446 15 N First St at Trimble Rd 1781 8 1714 59 Type of Conflict Intersection Total Conflicts PM Peak Period Conflicts (5 simulations of 5 hours each) Crossing Rear End Lane Change 1 579 0 559 20 2 577 1 556 20 3 605 1 583 21 4 595 2 574 19 5 586 2 559 25 Total 2942 6 2831 105 Average 588 1 566 21 St. Dev 11.7 0.8 11.7 2.3 Coefficient of Variation 0.02 0.70 0.02 0.11 1 267 1 246 20 2 259 1 240 18 3 219 0 205 14 4 244 1 225 18 5 246 1 231 14 Total 1235 4 1147 84 Average 247 1 229 17 St. Dev 18.3 0.4 15.9 2.7 Coefficient of Variation 0.07 0.56 0.07 0.16 1 313 2 295 16 2 276 0 263 13 3 282 1 262 19 4 301 0 272 29 5 293 1 273 19 Total 1465 4 1365 96 Average 293 1 273 19 St. Dev 14.8 0.8 13.3 6.0 Coefficient of Variation 0.05 1.05 0.05 0.31 1 92 1 89 2 2 86 1 81 4 3 97 1 93 3 4 96 1 91 4 5 94 0 92 2 Total 465 4 446 15 Average 93 1 89 3 St. Dev 4.4 0.4 4.8 1.0 Coefficient of Variation 0.05 0.56 0.05 0.33 1 362 2 344 16 2 356 4 341 11 3 371 0 362 9 4 337 1 325 11 5 355 1 342 12 Total 1781 8 1714 59 Average 356 2 343 12 St. Dev 12.5 1.5 13.1 2.6 Coefficient of Variation 0.04 0.95 0.04 0.22 N First St at Trimble Rd PM Peak Period Conflicts (5 hour simulation period) Intersection Simulation # Total Conflicts Type of Conflict N First St at E Brokaw N First St at Karina Ct N First St at Charcot Ave N First St at Component Dr Figure 17. Summary of PM Peak Hour Conflicts Note:  No light rail conflicts were observed or recorded.Â
TCRP Web-Only Document 53 55 ALTERNATIVE ANALYSIS The tasks below were the focus of the alternatives that were developed and analyzed: Task 7. Code an alternative speed increase for 40 mph and optimize signal timing (left-turn phase sequence and offsets) and detector locations accordingly. Refine the 40 mph scenario with adjustments to the change and clearance intervals (Yellow + All Red). Simulate an increase in traffic demand on the cross streets by 10%, 15%, and 20%. Simulate an increase in traffic demand for left turns by 10%, 15%, and 20%. Task 8. Code an alternative speed increase for 45 mph and optimize signal timing (left-turn phase sequence and offsets) and detector locations accordingly. Refine the 45 mph scenario with adjustments to the change and clearance intervals (Yellow + All Red). The following scenarios were modeled and analyzed for safety using the same guidelines for analysis as the existing conditions, so that a direct comparison could be conducted: ï· 40 mph LRV; No Change to any volume inputs or routing decisions ï· 45 mph LRV; No Change to any volume inputs or routing decisions ï· 40 mph LRV; 10%, 15%, and 20% increase in cross street volume inputs and demand for left turns (cross street and main-line). ï· 45 mph LRV; 10%, 15%, and 20% increase in cross street volume inputs and demand for left turns (cross street and main-line). With both AM and PM peak periods being analyzed under the conditions described above, a total of eighteen different files were created. In order to accurately model these conditions and the likely changes to be made in actual field operation, the following adjustments were made: ï· Adjust âtravel timeâ parameter in signal controllers for detectors, including remote detectors along the light rail track. This will account for the increased speed of the train and decreased projected arrival times from the location of each detector to the intersection. ï· Increase red clearance intervals of phases that may run before the transit phase ï· Adjust offsets to optimize progression on North First St. ï· Increase minimum green time for certain phases when the signal controller is in priority/recovery mode in order to avoid excessive queuing and cycle failures due to the increased demand for left turns. Detector Locations To effectively optimize the detector locations along the light rail track, the projected travel time values were changed rather than changing the physical location of the detectors. For the purpose of transit priority, the effect of decreasing the projected travel time for a detector in a given location is the equivalent of moving the detector further from the intersection (using existing travel time values), assuming the light rail vehicle is traveling at a higher speed than in existing conditions. The methodology for adjusting the projected travel times for the detectors was based on using the same assumptions that could be made when assigning a travel time to the detectors under existing conditions. These assumptions were that the travel times account for the projected time to accelerate, decelerate, dwell at a transit stop, etc. A spreadsheet was developed to separate the travel time that could be attributed to the train arriving as if it were traveling at a constant speed, and the time that was factored into the travel time value that could be attributed to the train accelerating, decelerating, or dwelling at a stop. When calculating the proposed
TCRP Web-Only Document 53 56 travel times, the additional time spent accelerating and decelerating from higher speeds was taken into consideration. Figure 18 shows the values assigned in adjusting the detector parameters. Clearance Intervals The clearance intervals for the phases that may run before the transit phase were increased in order to decrease the probability of a light rail vehicle colliding with an automobile, pedestrian, or bicycle. These phases corresponded to the through movements on the side streets and the left- turn movements on North First St. when they were operating as âleading turns.â An additional 0.5 seconds was added to these phases for both the 40 mph and 45 mph scenarios, in order to account for the LRV traveling at a faster speed, and therefore crossing the intersection in less time. The yellow clearance intervals were kept at the existing value of six seconds, as this is adequate time for the higher speed LRVs to clear the intersection. Optimizing Offsets The goal of adjusting offsets was to optimize the coordination and progression along North First St.. To accomplish this, the existing models were used absent of any light rail vehicles that would affect the normal operation of the signal controllers. Using the simulated volumes, a Synchro model was developed with the existing timings, for the purpose of optimizing the offsets using the optimize feature as well as manual adjustments based on the time-space diagram which the program outputs. These offsets were plugged into the signal controllers within the VISSIM model. Since VISSIM does not have an automated optimize feature for offsets, the offsets were adjusted further based on observations of multiple simulation runs. Following the optimization of the offsets on North First St., the light rail vehicles were entered back into the models. The apparent coordination of the signals may be impacted by the operation of the transit priority despite the offsets being optimized. This is due to the decrease or increase of green time during other phases in both priority and recovery modes which can influence progression. Method of Comparison To compare the model output of existing conditions to the alternative scenarios, the conflict data was processed in SSAM using a t-test for each peak period. The t-test is a commonly applied method of determining whether the means of two different data sets representing a larger population in an experiment are different at a statistically significant level. In order to compare the safety of the modeled scenarios to existing conditions, each type of conflict was tested for statistical significance (95-percent level of confidence) including a comparison of total conflicts, light rail related conflicts, crossing conflicts, rear end conflicts, and lane change conflicts.
TCRP Web-Only Document 53 57 Intersection with N First St Detector Number (Assigned In VISSIM model) Track Direction Existing Distance to Intersection Existing Travel Time Proposed Travel Time (40 mph) Proposed Travel Time (45 mph) Time to Arrival at Constant 35 mph Travel Time Not Attributed to Constant Speed Time to Arrival at Constant 40 mph Time to Arrival at Constant 45 mph 310 3808' 125 117 111 74.2 51.8 64.9 58.7 311 2327' 82 77 74 45.3 37.7 39.7 36.3 312 495' 14 14 14 9.6 5.4 8.4 8.5 316 736' 15 14 14 14.3 1.7 12.5 12.2 310 4307' 127 118 110 83.9 44.1 73.4 66.3 311 2693' 60 54 50 52.5 8.5 45.9 41.8 312 1402' 30 28 26 27.3 3.7 23.9 22.2 315 1692' 43 40 38 33.0 11.0 28.8 26.6 316 714' 25 24 24 13.9 12.1 12.2 11.8 310 3328' 110 103 98 64.8 46.2 56.7 51.4 311 2718' 90 84 80 52.9 38.1 46.3 42.2 312 1104' 33 31 30 21.5 12.5 18.8 17.7 315 2304' 85 80 77 44.9 41.1 39.3 35.9 316 1154' 33 31 30 22.5 11.5 19.7 18.5 334 3282' 105 98 93 63.9 42.1 55.9 50.7 311 1781' 45 42 39 34.7 11.3 30.4 28.0 312 1172' 24 22 21 22.8 2.2 20.0 18.8 314 3845' 121 113 106 74.9 47.1 65.5 59.3 315 2696' 61 55 51 52.5 9.5 46.0 41.8 316 1338' 26 24 22 26.1 0.9 22.8 21.3 312 410' 15 15 15 8.0 8.0 7.0 7.2 310 4047' 109 100 93 78.8 31.2 69.0 62.3 314 2890' 88 82 77 56.3 32.7 49.3 44.8 315 1347' 61 59 57 26.2 35.8 23.0 21.4 316 912' 23 22 21 17.8 6.2 15.5 14.8 Trimble Rd Arrival Time Values for Light Rail Vehicle Detectors (seconds) E Brokaw St Karina Ct Charcot Ave Component Dr N S S S S S S N N S S S N N N S S N N N S N N N N A. Alternative Comparison The primary reason for modeling an increase in Light Rail Vehicle speed was to analyze and determine if this would be done at the detriment to automobile, pedestrian, and cyclist safety, specifically left-turn and angle related conflicts. In the 16 models involving increased light rail Figure 18. Summary of Changes to LRV Detectors
TCRP Web-Only Document 53 58 No Significant Change Significant Decrease Significant Increase Legend vehicle speed (four volume alternatives, two speed alternatives, and two peak periods), there were no recorded conflicts involving Light Rail Vehicles. However, since intersection safety was the main concern, the conflicts involving other modes were analyzed and compared. The results of the t-tests for each peak period are displayed in numerical form in Figure 19 and Figure 20 for the AM and PM peak period, respectively. Figures 21 through 27 show a direct comparison between each alternative and the existing conditions, while Appendix C includes this data in tabular form. Figure 19. AM Peak Hour Conflicts t-test AM 40 mph 0 Percent AM 40 mph 10 Percent AM 40 mph 15 Percent AM 40 mph 20 Percent AM 45 mph 0 Percent AM 45 mph 10 Percent AM 45 mph 15 Percent AM 45 mph 20 Percent Existing AM (35 mph) -1.107 -5.289 -8.248 -10.636 -1.268 -4.981 -6.091 -11.39 AM 40 mph 0 Percent -4.228 -7.408 -9.986 -0.089 -3.886 -5.223 -10.819 AM 40 mph 10 Percent -5.115 -8.596 4.67 0.662 -2.361 -11.229 AM 40 mph 15 Percent -5.38 8.36 6.11 0.61 -6.699 AM 40 mph 20 Percent 10.868 9.286 4.26 1.516 AM 45 mph 0 Percent -4.299 -5.542 -12.354 AM 45 mph 10 Percent -2.811 -12.673 AM 45 mph 15 Percent -3.926 Existing AM (35 mph) NO YES YES YES NO YES YES YES AM 40 mph 0 Percent YES YES YES NO YES YES YES AM 40 mph 10 Percent YES YES YES NO YES YES AM 40 mph 15 Percent YES YES YES NO YES AM 40 mph 20 Percent YES YES YES NO AM 45 mph 0 Percent YES YES YES AM 45 mph 10 Percent YES YES AM 45 mph 15 Percent YES AM Peak Hour Total t values (All Conflicts) Significant AM 40 mph 0 Percent AM 40 mph 10 Percent AM 40 mph 15 Percent AM 40 mph 20 Percent AM 45 mph 0 Percent AM 45 mph 10 Percent AM 45 mph 15 Percent AM 45 mph 20 Percent Existing AM (35 mph) -0.693 -1.686 -2.213 -1.36 -1.692 -0.792 0 -1.461 AM 40 mph 0 Percent -0.368 -0.822 -0.667 -0.775 -0.169 0.632 -0.584 AM 40 mph 10 Percent -0.784 -0.506 -0.645 0.103 1.365 -0.391 AM 40 mph 15 Percent -0.098 -0.123 0.501 1.848 0.124 AM 40 mph 20 Percent 0.459 1.273 0.171 AM 45 mph 0 Percent 0.519 1.532 0.201 AM 45 mph 10 Percent 0.74 -0.347 AM 45 mph 15 Percent -1.321 Existing AM (35 mph) NO NO YES NO NO NO NO NO AM 40 mph 0 Percent NO NO NO NO NO NO NO AM 40 mph 10 Percent NO NO NO NO NO NO AM 40 mph 15 Percent NO NO NO NO NO AM 40 mph 20 Percent NO NO NO NO AM 45 mph 0 Percent NO NO NO AM 45 mph 10 Percent NO NO AM 45 mph 15 Percent NO AM Peak Hour Crossing t values Significant
TCRP Web-Only Document 53 59 No Significant Change Significant Decrease Significant Increase Legend AM 40 mph 0 Percent AM 40 mph 10 Percent AM 40 mph 15 Percent AM 40 mph 20 Percent AM 45 mph 0 Percent AM 45 mph 10 Percent AM 45 mph 15 Percent AM 45 mph 20 Percent Existing AM (35 mph) -1.01 -5.208 -7.406 -9.887 -1.031 -4.988 -5.852 -10.308 AM 40 mph 0 Percent -4.435 -6.891 -9.562 0.053 -4.179 -5.202 -10.155 AM 40 mph 10 Percent -3.917 -7.755 5.134 0.769 -2.22 -9.414 AM 40 mph 15 Percent -5.105 7.972 5.244 0.075 -5.527 AM 40 mph 20 Percent 10.568 8.74 3.697 1.549 AM 45 mph 0 Percent -4.91 -5.659 -11.783 AM 45 mph 10 Percent -2.742 -11.693 AM 45 mph 15 Percent -3.117 Existing AM (35 mph) NO YES YES YES NO YES YES YES AM 40 mph 0 Percent YES YES YES NO YES YES YES AM 40 mph 10 Percent YES YES YES NO YES YES AM 40 mph 15 Percent YES YES YES NO YES AM 40 mph 20 Percent YES YES YES NO AM 45 mph 0 Percent YES YES YES AM 45 mph 10 Percent YES YES AM 45 mph 15 Percent YES AM Peak Hour Rear-end t values Significant AM 40 mph 0 Percent AM 40 mph 10 Percent AM 40 mph 15 Percent AM 40 mph 20 Percent AM 45 mph 0 Percent AM 45 mph 10 Percent AM 45 mph 15 Percent AM 45 mph 20 Percent Existing AM (35 mph) -0.686 -0.799 -4.654 -4.037 -1.705 -0.617 -2.248 -5.312 AM 40 mph 0 Percent 0.05 -4.246 -3.62 -0.913 -0.032 -1.56 -4.961 AM 40 mph 10 Percent -6.19 -4.343 -1.935 -0.076 -2.754 -6.666 AM 40 mph 15 Percent -0.484 5.83 3.355 4.243 -1.257 AM 40 mph 20 Percent 3.817 3.122 3.1 -0.455 AM 45 mph 0 Percent 0.637 -1.633 -6.289 AM 45 mph 10 Percent -1.151 -4.046 AM 45 mph 15 Percent -5.016 Existing AM (35 mph) NO NO YES YES NO NO YES YES AM 40 mph 0 Percent NO YES YES NO NO NO YES AM 40 mph 10 Percent YES YES YES NO YES YES AM 40 mph 15 Percent NO YES YES YES NO AM 40 mph 20 Percent YES YES YES NO AM 45 mph 0 Percent NO NO YES AM 45 mph 10 Percent NO YES AM 45 mph 15 Percent YES AM Peak Hour Lane changing t values Significant Figure 19. (Continued) AM Peak Hour Conflicts t-test
TCRP Web-Only Document 53 60 No Significant Change Significant Decrease Significant Increase Legend Figure 20. PM Peak Hour Conflicts t-test PM 40 mph 0 Percent PM 40 mph 10 Percent PM 40 mph 15 Percent PM 40 mph 20 Percent PM 45 mph 0 Percent PM 45 mph 10 Percent PM 45 mph 15 Percent PM 45 mph 20 Percent Existing PM (35 mph) 1.144 1.198 -2.337 -5.219 0.759 1.079 -2.504 -9.26 PM 40 mph 0 Percent -0.187 -2.613 -4.826 -0.502 -0.077 -2.615 -6.998 PM 40 mph 10 Percent -2.838 -5.323 -0.376 0.103 -2.956 -8.248 PM 40 mph 15 Percent -2.508 2.54 2.587 0.355 -4.487 PM 40 mph 20 Percent 5.077 4.84 3.152 -1.365 PM 45 mph 0 Percent 0.425 -2.614 -8.018 PM 45 mph 10 Percent -2.593 -7.09 PM 45 mph 15 Percent -5.798 Existing PM (35 mph) NO NO YES YES NO NO YES YES PM 40 mph 0 Percent NO YES YES NO NO YES YES PM 40 mph 10 Percent YES YES NO NO YES YES PM 40 mph 15 Percent YES YES YES NO YES PM 40 mph 20 Percent YES YES YES NO PM 45 mph 0 Percent NO YES YES PM 45 mph 10 Percent YES YES PM 45 mph 15 Percent YES PM Peak Hour Total t values (All Conflicts) Significant PM 40 mph 0 Percent PM 40 mph 10 Percent PM 40 mph 15 Percent PM 40 mph 20 Percent PM 45 mph 0 Percent PM 45 mph 10 Percent PM 45 mph 15 Percent PM 45 mph 20 Percent Existing PM (35 mph) 0.453 -0.771 -0.523 -1.945 -0.478 -1.171 -0.351 -0.822 PM 40 mph 0 Percent -1.006 -0.802 -2.252 -1.033 -1.383 -0.73 -1.192 PM 40 mph 10 Percent 0.275 -0.73 0.566 -0.389 0.518 0.203 PM 40 mph 15 Percent -1.123 0.272 -0.673 0.241 -0.117 PM 40 mph 20 Percent 1.753 0.251 1.554 1.159 PM 45 mph 0 Percent -0.998 -0.526 PM 45 mph 10 Percent 0.93 0.639 PM 45 mph 15 Percent -0.435 Existing PM (35 mph) NO NO NO YES NO NO NO NO PM 40 mph 0 Percent NO NO YES NO NO NO NO PM 40 mph 10 Percent NO NO NO NO NO NO PM 40 mph 15 Percent NO NO NO NO NO PM 40 mph 20 Percent NO NO NO NO PM 45 mph 0 Percent NO NO NO PM 45 mph 10 Percent NO NO PM 45 mph 15 Percent NO PM Peak Hour Crossing t values Significant
TCRP Web-Only Document 53 61 No Significant Change Significant Decrease Significant Increase Legend Figure 7. (Continued) PM Peak Hour Conflicts tâtest PM 40 mph 0 Percent PM 40 mph 10 Percent PM 40 mph 15 Percent PM 40 mph 20 Percent PM 45 mph 0 Percent PM 45 mph 10 Percent PM 45 mph 15 Percent PM 45 mph 20 Percent Existing PM (35 mph) -0.459 -1.335 -2.604 -1.874 -1.145 -1.039 -1.528 -4.51 PM 40 mph 0 Percent -0.435 -1.375 -1.262 -0.304 -0.403 -0.861 -2.869 PM 40 mph 10 Percent -1.937 -1.222 0.275 -0.055 -0.723 -4.579 PM 40 mph 15 Percent -0.351 2.168 1.127 0.332 -2.758 PM 40 mph 20 Percent 1.336 1.022 0.517 -1.062 PM 45 mph 0 Percent -0.218 -0.864 -4.755 PM 45 mph 10 Percent -0.55 -2.958 PM 45 mph 15 Percent -2.006 Existing PM (35 mph) NO NO YES YES NO NO NO YES PM 40 mph 0 Percent NO NO NO NO NO NO YES PM 40 mph 10 Percent YES NO NO NO NO YES PM 40 mph 15 Percent NO YES NO NO YES PM 40 mph 20 Percent NO NO NO NO PM 45 mph 0 Percent NO NO YES PM 45 mph 10 Percent NO YES PM 45 mph 15 Percent YES PM Peak Hour Lane changing t values Significant PM 40 mph 0 Percent PM 40 mph 10 Percent PM 40 mph 15 Percent PM 40 mph 20 Percent PM 45 mph 0 Percent PM 45 mph 10 Percent PM 45 mph 15 Percent PM 45 mph 20 Percent Existing PM (35 mph) 1.257 1.476 -2.042 -5.149 0.935 1.436 -2.063 -7.556 PM 40 mph 0 Percent -0.05 -2.483 -4.77 -0.417 0.086 -2.445 -6.266 PM 40 mph 10 Percent -2.783 -5.338 -0.421 0.149 -2.818 -7.16 PM 40 mph 15 Percent -2.631 2.361 2.661 0.298 -4.173 PM 40 mph 20 Percent 4.928 5.008 3.182 -1.264 PM 45 mph 0 Percent 0.528 -2.343 -6.706 PM 45 mph 10 Percent -2.648 -6.585 PM 45 mph 15 Percent -4.997 Existing PM (35 mph) NO NO YES YES NO NO YES YES PM 40 mph 0 Percent NO YES YES NO NO YES YES PM 40 mph 10 Percent YES YES NO NO YES YES PM 40 mph 15 Percent YES YES YES NO YES PM 40 mph 20 Percent YES YES YES NO PM 45 mph 0 Percent NO YES YES PM 45 mph 10 Percent YES YES PM 45 mph 15 Percent YES PM Peak Hour Rear-end t values Significant Figure 20. (Continued) PM Peak Hour Conflicts t-test
TCRP Web-Only Document 53 62 Figure 21. AM Peak Hour Total Conflicts
TCRP Web-Only Document 53 63 Figure 22. AM Peak Hour Rear-end Conflicts
TCRP Web-Only Document 53 64 Figure 23. AM Peak Hour Lane Change Conflicts
TCRP Web-Only Document 53 65 Figure 24. PM Peak Hour Total Conflicts
TCRP Web-Only Document 53 66 Figure 25. PM Peak Hour Crossing Conflicts
TCRP Web-Only Document 53 67 Figure 26. PM Peak Hour Rear-end Conflicts
TCRP Web-Only Document 53 68 Figure 27. PM Peak Hour Lane Change Conflicts
TCRP Web-Only Document 53 69 Critical Observations and Changes In the processing of conflicts involving automobiles, pedestrians, and bicycles (there were no LRV conflicts recorded), it is important to note the changes made to alternative conditions that may influence conflicts, as well as observations made in all of the models which may explain increases and decreases in conflicts between alternatives. One key observation made in both existing and alternative condition models occurred at the intersection of North First St. and East Brokaw Road. This observation identified risky behavior from eastbound left-turning vehicles. In both existing and alternative models, the corresponding phase for this movement often reached its maximum green time due to high demand, and automobiles would proceed through the intersection on yellow, sometimes not clearing the intersection before the opposing westbound through movement had a green light. If a pedestrian began to cross on the north side while the vehicle was still in the intersection, the driver would yield to the pedestrian, blocking one westbound through lane. In reality, the driver in the outside turn lane would most likely make a lane-change to the inner lane to avoid the pedestrian, or the pedestrian would yield to the vehicle. However, in the simulation, conflict areas are setup so that vehicles must yield to pedestrians who cross exclusively on âwalkâ and flashing âdonât walkâ signals, since this is common for permitted right-turning and left-turning vehicles. This occurrence, which appears to occur randomly, could explain a variation in the crossing conflicts between models at the intersection of East Brokaw Road and North First St. In the existing conditions model, and currently in the field, the phases corresponding to the eastbound and westbound through movements on Trimble Road at North First St. are set to max recall in the signal controller. Because these phases were recalling to their maximum splits, transit priority was not operating as efficiently as it would if these phases were actuated, because a call from a light rail vehicle could not decrease the green time on Trimble Road in order to serve North First St. sooner. In the future conditions models, the phases corresponding to the through movements on Trimble Road were set to min recall, and were actuated. This allowed the transit priority to operate more efficiently and decreased delay on North First St., while slightly increasing the queues on Trimble Road. This change may have an effect on the number of conflicts at this intersection. a. 40 mph LRV: No change to volume inputs or routing decisions The first alternative modeled involves the scenario that is essentially the base conditions (35 mph), but with changes made to the light rail operating speed, offsets, clearance intervals, and detector parameters described earlier in Section VI of the report. No changes were made to volumes, heavy vehicle percentages, or other parameters directly relating to the composition or characteristics of automobiles. The results of the t-test directly comparing conflicts by type show no significant increase or decrease in crossing, lane change, and rear-end collisions. This is concurrent with the test showing no significant change in the total number of collisions. On an individual intersection basis, the number of crossing conflicts did increase at Trimble Road and Charcot Avenue during the AM peak period. During the PM peak period, the number of conflicts recorded for this alternative increased at the intersection of East Brokaw Road. Again, it is critical to note that there were no recorded conflicts with light rail vehicles, and that the increase and decrease of conflicts by conflict type, location, and peak period fluctuated compared to the conflicts recorded under existing conditions. The conflict results of the 40 mph scenario are concurrent with the
TCRP Web-Only Document 53 70 existing conditions results, in that East Brokaw St. and Trimble Road have the greatest number of conflicts and risky behavior. b. 45 mph LRV: No change to volume inputs or routing decisions This alternative retains the same parameters as the first alternative (40 mph LRV: No change to volume inputs or routing decisions), except for modified detector travel time parameters on the light rail track, and a light rail vehicle speed of 45 mph. There were no recorded conflicts involving light rail vehicles. There were a greater number of crossing conflicts recorded at the intersections at East Brokaw St. and Trimble Road, compared to the existing conditions. However, the t-test comparing the alternative to existing conditions showed that simulating an increased light rail vehicle speed from 35 mph to 45 mph did not significantly increase or decrease any of the types of conflicts when the network was analyzed as a whole. The conflict results of the 45 mph scenario are concurrent with the existing conditions results, in that East Brokaw St. and Trimble Road have the greatest number of conflicts and risky behavior. c. 40 mph LRV: 10% increase in cross-street volumes and left-turn demand on North First Street This alternative involving increasing the light rail vehicle speed to 40 mph and increasing the cross-street volumes and main-line left-turn demand by 10% yielded no LRV related conflicts, while there was an increase in the total number of conflicts that was significant when compared to the existing conditions. However, there was no significant increase in crossing conflicts and lane-change conflicts. It is not unusual that the number of rear-end conflicts increased due to the increase in cross-street volume and more vehicles approaching a queue on these approaches. Crossing conflicts at particular intersections appeared to increase at the intersection of East Brokaw St., while fluctuating at others. d. 45 mph LRV: 10% increase in cross-street volumes and left-turn demand on North First Street This alternative involving increasing the light rail vehicle speed to 45 mph and increasing the cross-street volumes and main-line left-turn demand by 10% yielded no LRV related conflicts, while there was an increase in the total number of conflicts that was significant when compared to the existing conditions, just as in the 40 mph scenario with the same increase in volumes. Crossing conflicts at particular intersections appeared to increase at the intersection of East Brokaw St., while fluctuating at others when compared to existing conditions. A t-test was also performed comparing alternatives of the same volume growth and increase in left-turn demand, but with different light rail vehicle speeds. This alternative, with a 45 mph light rail vehicle speed did not significantly yield more or less conflicts, compared to the alternative with the same volumes and a 40 mph light rail vehicle speed. e. 40 mph LRV: 15% increase in cross-street volumes and left-turn demand on North First Street This alternative involving increasing the light rail vehicle speed to 40 mph and increasing the cross-street volumes and main-line left-turn demand by 15% yielded no LRV related conflicts. There was an increase in the total number of conflicts, crossing conflicts (AM only), lane-change conflicts, and rear-end conflicts that was significant when compared to the existing conditions. Compared to existing conditions, crossing conflicts at particular intersections increased at the intersection of East Brokaw St. and Trimble Road, while fluctuating at others. Compared to the
TCRP Web-Only Document 53 71 models with a 10% increase in cross-street volumes and left-turn demand, there was a significant increase in total conflicts, rear-end conflicts, and lane-change conflicts. f. 45 mph LRV: 15% increase in cross-street volumes and left-turn demand on North First Street This alternative involving increasing the light rail vehicle speed to 45 mph and increasing the cross-street volumes and main-line left-turn demand by 15% yielded no LRV related conflicts. There was an increase in the total number of conflicts, lane-change conflicts, and rear-end conflicts that was significant when compared to the existing conditions. Compared to existing conditions, crossing conflicts at particular intersections increased at the intersection of East Brokaw St., and Trimble Rd., while fluctuating at others. Compared to the models with a mere 10% increase in cross-street volumes and left-turn demand, there was a significant increase in total conflicts, rear-end conflicts, and lane-change conflicts. g. 40 mph LRV: 20% increase in cross-street volumes and left-turn demand on North First Street This alternative involving increasing the light rail vehicle speed to 40 mph and increasing the cross-street volumes and main-line left-turn demand by 20% yielded no LRV related conflicts. There was a significant increase in the total number of conflicts, crossing conflicts (PM only), lane-change conflicts, and rear-end conflicts when compared to the existing conditions. Compared to existing conditions, crossing conflicts at particular intersections increased at the intersection of East Brokaw St., and Trimble Road, while fluctuating at others. Based on the increase in volumes, and demand for main-line left-turns, extensive queuing was observed which appears to have a correlation with rear-end conflicts. The increase in volumes also appears to be positively correlated with lane-change conflicts. There appears to be a slight correlation between an increase in volumes and crossing conflicts. However, as the volumes near or exceed capacity, the throughput does not increase linearly, so crossing conflicts were not observed to increase as great as they did in the other incremental volume increase (i.e. 0% to 10% and 10% to 15%). h. 45 mph LRV: 20% increase in cross-street volumes and left-turn demand on North First Street This alternative involving increasing the light rail vehicle speed to 45 mph and increasing the cross-street volumes and main-line left-turn demand by 20% yielded no LRV related conflicts. There was a significant increase in the total number of conflicts, lane-change conflicts, and rear- end conflicts when compared to the existing conditions. Compared to existing conditions, crossing conflicts at particular intersections increased at the intersection of East Brokaw St., and Trimble Road, while fluctuating at others, similar to the other alternatives modeled. The results were for this alternative were similar to the alternative with the same volume increase with a 40 mph LRV, as they are not significantly different in any of the conflicts tested. DELAY COMPARISON Following the testing of alternatives and comparison of conflicts, queues and delays at the study intersections were compiled for existing conditions and scenarios with 20% increase in cross- street and left-turn traffic volumes As expected, delays and queues associated with the cross- streets and turning movements increased as overall traffic volumes increased. Long queuing and spillback was observed at key intersections in the increased volume scenarios. However, due to all roadways having physical separation from the light rail right-of-way, when spillback
TCRP Web-Only Document 53 72 occurred, it was either on a cross-street, or upstream from the intersection at which the spillback occurred. There were no instances observed of excessive queues backing onto the light rail crossings. Figure 28 shows the VISSIM output of average delays and maximum queues by movement between the Existing AM Peak model and the scenario with a 20% increase cross- street and mainline left-turn traffic volumes. Figure 29 shows the delays and queues for the scenario described above, but with the light rail vehicle speed at 45 mph. Figure 30 and Figure 31 reflect the PM peak hour output for the scenarios described above.
TCRP Web-Only Document 53 73 (27) (34) (69) (103) (191) (191) 25 32 72 41 (32) 97 185 185 498 (320) 48 (38) 498 (320) 71 (69) 498 (320) (69) 69 (296) 364 (37) 43 (296) 364 (7) 9 95 32 29 (210) 279 821 821 821 (91) (34) (30) (815) (815) (815) (3) (12) (66) (36) (219) (219) 2 10 81 34 (34) 37 271 271 120 (96) 58 (54) 211 (187) 57 (54) 211 (187) (37) 53 (52) 55 (49) 48 (52) 55 (1) 1 76 12 12 0 576 576 439 (82) (12) (11) (680) (680) (543) (6) (17) (72) (199) (199) (199) 8 22 68 36 (34) 244 244 244 131 (93) 61 (62) 223 (185) 64 (65) 223 (185) (34) 36 (93) 131 (62) 61 68 31 29 (185) 223 556 556 426 (65) 64 (66) (28) (25) (185) 223 (570) (570) (440) (1) (7) (72) (168) (168) (168) 2 6 67 183 183 183 (73) 62 (36) 36 0 72 5 0 622 622 (11) 11 (79) (5) (36) 36 (434) (434) (9) (48) (67) (211) (203) (203) 10 60 73 9 (6) 225 216 216 1665 (707) 61 (31) 1665 (902) 60 (65) 1675 (902) (112) 90 (792) 846 (35) 36 (792) 846 (7) 9 83 55 25 (792) 846 574 574 574 (77) (40) (16) (445) (445) (445) Maximum Queues (ft)Delays for AM 40 mph LRV with 20% Volume Increase vs. Existing Delays (s) ## = Alternative Scenario (##) = Existing ## = Alternative Scenario (##) = Existing Delays for 40 mph LRV with 20% Volume Turn Volume Increase vs. Existing Delays (s)  ##  Alternative Scenario Delay (##) = Existing Delay Maximum Queues (ft)  ## = Alternative Scenario Delay (##) = Existing Delay Figure 28. AM Peak Delays and Queues for Scenario with 40 mph LRV and 20% Turning Volume Increase vs. Existing Conditions
TCRP Web-Only Document 53 74 Figure 29. AM Peak Delays and Queues for Scenario with 45 mph LRV and 20% Turning Volume Increase vs. Existing Conditions (27) (34) (69) (103) (191) (191) 24 33 75 44 (32) 99 187 187 495 (320) 48 (38) 495 (320) 70 (69) 495 (320) (69) 71 (296) 366 (37) 43 (296) 366 (7) 9 93 33 30 (210) 280 911 911 911 (91) (34) (30) (815) (815) (815) (3) (12) (66) (36) (219) (219) 2 10 84 33 (34) 41 273 273 130 (96) 57 (54) 221 (187) 57 (54) 221 (187) (37) 52 (52) 56 (49) 49 (52) 56 (1) 1 80 13 12 0 629 629 492 (82) (12) (11) (680) (680) (543) (6) (17) (72) (199) (199) (199) 8 22 68 36 (34) 244 244 244 130 (93) 59 (62) 221 (185) 68 (65) 221 (185) (34) 36 (93) 130 (62) 59 65 30 28 (185) 221 581 581 451 (65) 68 (66) (28) (25) (185) 221 (570) (570) (440) (1) (7) (72) (168) (168) (168) 2 6 66 186 186 186 (73) 65 (36) 37 0 73 5 0 542 542 (11) 11 (79) (5) (36) 37 (434) (434) (9) (48) (67) (211) (203) (203) 11 60 72 9 (6) 232 223 223 1677 (707) 26 (31) 1677 (902) 61 (65) 1677 (902) (112) 89 (792) 806 (35) 37 (792) 806 (7) 8 86 56 27 (792) 806 602 602 602 (77) (40) (16) (445) (445) (445) Maximum Queues (ft)Delays AM 45 mph 20% Volume Increase (s) Delays for 45 mph LRV with 20% Turn Volume Increase vs. Existing Delays (s)   ## = Alternative Scenario Delay (##) = Existing Delay Maximum Queues (ft)   ## = Alternative Scenario Delay (##) = Existing DelayÂ
TCRP Web-Only Document 53 75 Figure 30. PM Peak Delays and Queues for Scenario with 45 mph LRV and 20% Turning Volume Increase vs. Existing Conditions (32) (37) (73) (409) (497) (497) 29 33 73 38 (28) 388 476 476 398 (271) 46 (37) 398 (271) 73 (70) 398 (271) (67) 70 (336) 522 (39) 49 (336) 522 (11) 18 78 30 24 (249) 436 270 270 270 (82) (33) (26) (220) (220) (220) (2) (9) (76) (27) (8) (201) 2 15 72 47 (45) 24 9 283 249 (186) 61 (61) 340 (277) 62 (61) 340 (277) (49) 44 (72) 84 (48) 46 (72) 84 (3) 3 80 8 6 0 0 237 237 100 (78) (9) (8) (201) (201) (64) (23) (20) (64) (420) (420) (420) 21 18 73 52 (50) 425 425 425 668 (504) 59 (59) 760 (596) 73 (69) 760 (596) (63) 64 (223) 249 (50) 47 70 23 18 (223) 249 270 270 140 (39) 37 (62) (21) (17) (159) 185 (248) (248) (121) (3) (10) (27) (314) (314) (314) 4 11 47 370 370 370 (27) 43 (123) 180 0 0 46 6 0 0 212 212 (12) 16 (24) (5) (123) 180 (185) (185) (15) (44) (55) (634) (625) (625) 11 33 78 2 (2) 569 568 568 815 (365) 49 (39) 997 (559) 63 (50) 997 (559) (56) 76 (347) 478 (42) 52 (347) 478 (11) 18 74 35 10 (347) 478 229 229 229 (58) (40) (10) (270) (270) (270) Maximum Queues (ft)Delays PM 40 mph 20% Volume Increase (s) Delays for 40 mph LRV with 20% Turn Volume Increase vs. Existing Delays (s)   ## = Alternative Scenario Delay (##) = Existing Delay Maximum Queues (ft)  ## = Alternative Scenario Delay (##) = Existing DelayÂ
TCRP Web-Only Document 53 76 Figure 31. PM Peak Delays and Queues for Scenario with 45 mph LRV and 20% Turning Volume Increase vs. Existing Conditions (32) (37) (73) (409) (497) (497) 31 34 75 38 (28) 405 493 493 405 (271) 45 (37) 405 (271) 74 (70) 405 (271) (67) 71 (336) 533 (39) 49 (336) 533 (11) 18 69 30 24 (249) 447 244 244 244 (82) (33) (26) (220) (220) (220) (2) (9) (76) (27) (8) (201) 2 10 80 47 (45) 21 8 312 247 (186) 62 (61) 338 (277) 63 (61) 338 (277) (49) 48 (72) 84 (48) 46 (72) 84 (3) 3 77 7 6 0 0 205 205 68 (78) (9) (8) (201) (201) (64) (23) (20) (64) (420) (420) (420) 19 17 76 51 (50) 436 436 436 667 (504) 60 (59) 759 (596) 74 (69) 759 (596) (63) 65 (223) 256 (50) 47 70 23 18 (223) 256 257 257 132 (39) 36 (62) (21) (17) (159) 193 (248) (248) (121) (3) (10) (27) (314) (314) (314) 4 11 51 366 366 366 (27) 44 (123) 183 0 0 46 6 0 0 193 193 (12) 15 (24) (5) (123) 183 (185) (185) (15) (44) (55) (634) (625) (625) 12 33 79 1 (2) 582 589 589 968 (365) 45 (39) 1106 (559) 54 (50) 1106 (559) (56) 74 (347) 435 (42) 48 (347) 435 (11) 16 72 35 10 (347) 435 216 216 216 (58) (40) (10) (270) (270) (270) Maximum Queues (ft)Delays PM 45 mph 20% Volume Increase (s) Maximum Queues (ft)   ## = Alternative Scenario Delay (##) = Existing Delay Delays for 45 mph LRV with 20% Turn Volume Increase vs. Existing Delays (s)   ## = Alternative Scenario Delay (##) = Existing DelayÂ
TCRP Web-Only Document 53 77 PRELIMINARY CONCLUSIONS The results of the simulation did not demonstrate any change or significant evidence of an increase in LRV-related conflicts that are associated with increasing the operating speed of light rail vehicles. Likewise, the increase in the number of crossing type conflicts did not demonstrate a statistical significance among the various scenarios associated with increases in LRV speeds and traffic volumes.