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From page 83...
... P A R T I I Guide for Performance Measures in Snow and Ice Control Operations
From page 85...
... 85 The purpose of the Guide for Performance Measures in Snow and Ice Control Operations (referred to as the guide henceforth) is to provide insight on developing a performance framework for snow and ice operation management, helping decision makers to identify adjustments that can be made to manage resources effectively through the use of the proposed performance measures.
From page 86...
... 86 Performance Measures in Snow and Ice Control Operations • Performance measures identified by agencies need to be simple and easily understood not only by their stakeholders but also by their own staff. The following section defines how input, output, outcome, and impact categories are used in the guide.
From page 87...
... Introduction 87 peer agencies. Finally, researchers and contractors for agencies responsible for winter maintenance can use the guide as a resource for information about the state of the practice with respect to performance measurement for winter maintenance.
From page 88...
... 88 Performance Measures in Snow and Ice Control Operations with different existing capabilities, from those that are beginning the process of collecting data to high-capability agencies that are able to adequately capture outcome measures. The guidance is structured into four chapters and 10 steps, as shown in Figure 1.
From page 89...
... 89 Four steps are required for defining performance measures, as shown in Figure 2. C H A P T E R I Defining Performance Measures Defining Measures Figure 2.
From page 90...
... 90 Performance Measures in Snow and Ice Control Operations Question Options Impact on Performance Expectations and Measurement How important is snow and ice control to the agency's mission? High priority.
From page 91...
... Defining Performance Measures 91 necessary that there be a way to measure the achievement of the objective. In other words, the operational objectives drive the performance standards.
From page 92...
... 92 Performance Measures in Snow and Ice Control Operations In some cases, an agency might not want to specify an LOS during the event, which is likely when an agency is willing to close roads as part of the winter response or if transit service is suspended. The reason for defining an LOS during an event is twofold: • It establishes an expectation based on severity and type of roadway on what the agency is expected to provide, and • When contractors are used, having an LOS during an event allows for monitoring the response quality more effectively.
From page 93...
... Defining Performance Measures 93 Ways to Define LOS During an Event Approach Comments Maximum accumulation during the course of the event (Measured)
From page 94...
... 94 Performance Measures in Snow and Ice Control Operations not likely to have the same recovery targets. Objectively defining what constitutes "recovery" or is a return to normal is the primary challenge in measuring this objective (see Box 2)
From page 95...
... Defining Performance Measures 95 Travel Reliability During Event This measure is closely related to LOS and attempts to determine the drop in travel reliability due to a snow and ice event. Travel reliability is called out as a separate objective because of its potential for providing more trip- or route-based assessment of impact (as opposed to more segment-level LOS)
From page 96...
... 96 Performance Measures in Snow and Ice Control Operations Figure 7 shows an example of travel times over a hypothetical corridor both during normal weather and adverse weather; Table 4 illustrates computation for BI and PTI. During adverse weather events, each of these indices over the selected corridors should be within an acceptable difference compared to the indices in the absence of adverse weather.
From page 97...
... Defining Performance Measures 97 Measures Final Rule. The rule established five performance measures as the 5-year rolling averages for (1)
From page 98...
... 98 Performance Measures in Snow and Ice Control Operations et al. 1999; Ramakrishna and Viraraghavan 2005; Fay and Shi 2012)
From page 99...
... Defining Performance Measures 99 winter maintenance activities. Service-level thresholds vary by type of roadway and winter severity but are often set by an agency as a surrogate for crash risk and to some extent mobility needs.
From page 100...
... 100 Performance Measures in Snow and Ice Control Operations Service-level thresholds can be stated in one of the following forms: • Road conditions–related. Based on assessment by field personnel into LOS A to F (see example later in the section)
From page 101...
... Defining Performance Measures 101 • The accuracy of this measure will depend on the ability to report service levels consistently during an event, which could differ significantly between urban and rural areas or by road type. • Subjectivity is a concern for service levels based on field reports since different reporters may view road conditions differently.
From page 102...
... 102 Performance Measures in Snow and Ice Control Operations area, these designations need to be known for each road segment. Average travel speeds will be needed to calculate speed-related threshold.
From page 103...
... Defining Performance Measures 103 5. Obtain all observations of the service-level threshold that occurred during the event for affected segments As noted in Step 2, data logged by agency personnel in the field, law enforcement, citizen reporters, and RWIS stations should indicate a measurement of the service-level threshold and a time stamp of the observation.
From page 104...
... 104 Performance Measures in Snow and Ice Control Operations • Performance target. Desired time to reach a defined pavement condition, which may vary by roadway segment priority.
From page 105...
... Defining Performance Measures 105 Performance Target Performance Target Description Illustration LOS D (poor winter driving conditions) Travel is challenging for most vehicles properly equipped for winter driving.
From page 106...
... 106 Performance Measures in Snow and Ice Control Operations mitigate some of the subjectivity but not all. In general, field personnel such as snowplow drivers are required to report conditions.
From page 107...
... Defining Performance Measures 107 condition may be used by different agencies, or within an agency for more rural or lower functional class roadways. For instance, an agency may define as acceptable a duration of 3 h to achieve 95% bare pavement for Interstate highways and urban U.S.
From page 108...
... 108 Performance Measures in Snow and Ice Control Operations 9. Calculate frequency of meeting regain time target for each roadway segment for the winter season For each segment, identify the number of winter events where the performance target was met and divide by the total number of winter events for which a value of regain time was calculated for that segment.
From page 109...
... Defining Performance Measures 109 • Day of week. Higher TTI may be acceptable for certain days (e.g., Saturdays, Sundays, holidays)
From page 110...
... 110 Performance Measures in Snow and Ice Control Operations designations need to be known for each road segment. Average travel speeds will be needed to calculate a travel speed–related threshold.
From page 111...
... Defining Performance Measures 111 in the "injury status" data element (Governors Highway Safety Administration and U.S.
From page 112...
... 112 Performance Measures in Snow and Ice Control Operations Variations in the Measure This measure can be reported in ways that may be more helpful and relevant to winter maintenance operations given the availability of resources and quality data: • Winter season fatal or serious injury crashes. The number of all fatal or serious injury crashes over the designated winter season period.
From page 113...
... Defining Performance Measures 113 Data Elements Required for the Measure Required Data • Fatal crash records. At a minimum, the number of fatal crashes occurring during each winter season month is needed.
From page 114...
... 114 Performance Measures in Snow and Ice Control Operations 5. Obtain start and end times for winter events The start and end times may be approximated for each road segment based on a nearby or regional observation point(s)
From page 115...
... Defining Performance Measures 115 Measure Definition This performance measure analyzes the satisfaction of transportation system users during winter events by tracking traveler feedback at a regional or statewide level. Traveler satisfaction and demographic data are gathered through periodic surveys, focus groups, or other approaches.
From page 116...
... 116 Performance Measures in Snow and Ice Control Operations Data Elements Required for the Measure • Demographic information. Socioeconomic data that can be used to characterize households.
From page 117...
... Defining Performance Measures 117 Measure Definition This performance measure is a highly visible parameter of local and state expenditures. The main challenge is to develop a monetization approach that captures the complexity that exists in most state and local agencies as well as their limited ability to control the costs.
From page 118...
... 118 Performance Measures in Snow and Ice Control Operations Data Elements Required for the Measure • Unit cost. Cost of each unit of every resource used in winter maintenance activities.
From page 119...
... Defining Performance Measures 119 Agencies often review material usage as an indicator rather than a performance measure. Material usage alone is not an effective performance measure.
From page 120...
... 120 Performance Measures in Snow and Ice Control Operations amount or weighing the material as it is loaded, using onboard data to collect the amount of material dispensed, or by operators keeping good records of the material being loaded and used and the material returned at the end of an event. These data should be compiled per event and per season and should include materials used in pre-storm operations and in-storm operations in order to capture all the material being used.
From page 121...
... Defining Performance Measures 121 4. Collect the data Data should be collected following each event, and data should be compiled if a yearly total is desired.
From page 122...
... 122 Performance Measures in Snow and Ice Control Operations add elements if necessary. For this particular methodology, only storm-related elements are suggested for use.
From page 123...
... Defining Performance Measures 123 that are not representative of the entire population. These points can occur as a result of instrument error or abnormal conditions (i.e., unusual weather events for the time of year or location, such as snow in the state Florida in December)
From page 124...
... 124 Performance Measures in Snow and Ice Control Operations f. Steps c and d provide a model to obtain a final SSI when more than one element is selected to characterize the severity of a storm.
From page 125...
... Defining Performance Measures 125 normalized to obtain a less biased WSI. If in the previous example for SSI, precipitation is selected as the sole element of analysis, one could standardize it by coverage, yielding a WSI measured as average inches of snow per lane mile per day for heavy winter areas or average inches of snow per lane mile per month for milder winter areas.
From page 126...
... 126 Performance Measures in Snow and Ice Control Operations Source: Matthews et al., 2017. Figure 8.
From page 127...
... 127 The implementation stage involves the steps shown in Figure 9. C H A P T E R I I Implementing Performance Measures Implementing Measures Figure 9.
From page 128...
... 128 Performance Measures in Snow and Ice Control Operations or bare pavement and the time it was reported relative to the end of the event. Agencies with more established performance measurement programs may have the capabilities and resources to support training programs and enhanced, electronic reporting methods for agency personnel and citizen reporters that allow for more consistent, time-stamped reports, which would allow for a more precise, segment-level performance measurement for return to bare pavement.
From page 129...
... Implementing Performance Measures 129 performance. The PSIC is easy to use and low in cost, but it is a subjective measure because it is based on the perspective of the individual collecting the information.
From page 130...
... 130 Performance Measures in Snow and Ice Control Operations Typically, the measurement and recording of road condition reports are performed by plow drivers or other maintenance personnel while out on the roads. Reports are often submitted by radio or onboard device.
From page 131...
... Implementing Performance Measures 131 • In Ohio, basic air and pavement data from the 174 RWIS sites throughout the state are integrated into the Buckeye RCRS every 5 min. This intake of RWIS data provides additional information to travelers and enables internal Ohio DOT staff to view the weather information through the RCRS, which is particularly helpful when updating the manual road weather reports.
From page 132...
... 132 Performance Measures in Snow and Ice Control Operations road_weather.htm) is a valuable tool that can be used to perform a general assessment of an agency's capability level in key areas.
From page 133...
... 133 Two primary steps are identified in this chapter, as shown in Figure 10. C H A P T E R I I I Using Performance Information Using Measures Figure 10.
From page 134...
... 134 Performance Measures in Snow and Ice Control Operations could also be useful. The following are some different types of target-setting methods; rarely does a target-setting process fit neatly into one of these categories: • Policy-driven methods (established by executive management or a legislative body, which might arise because of public discontent with transportation issues)
From page 135...
... Using Performance Information 135 • Assess why they are setting the snow and ice control operation targets; • Link performance to the agency's overall and winter maintenance specific objectives, resources, and requirements; and • Use the agency's overall and winter maintenance purposes to inform target parameters and guide target establishment. Step 2 for Setting Targets – Set Target Parameters The next step is to define the target parameters.
From page 136...
... 136 Performance Measures in Snow and Ice Control Operations • Capital project commitments, • Budget and resource constraints, • Senior management directives, • Agency jurisdiction, • Agency goals and priorities, and • Planned operational activities. Other important considerations that agencies need to consider are: • Fiscal limitations and trade-offs, • Constraints and existing commitments, both within an agency and to stakeholders, • How factors will change over the time span of a target, • Risk associated with each of the factors (including magnitude and likelihood of risk)
From page 137...
... Using Performance Information 137 • Documenting key decisions and providing transparent information to explain the rationale around target choice: – Establishing project selection choices that will affect performance and link to target to decisions, and – Using the tools available to show link between funded projects and their impact on the target (see Box 7 for an example of how to present performance results)
From page 138...
... 138 Performance Measures in Snow and Ice Control Operations from season to season by district and statewide, ending with the final results of how often Minnesota DOT met bare-lane targets. Some agencies, such as the Idaho DOT, have experimented with dashboards to convey information with a higher frequency (see Figure 13)
From page 139...
... Using Performance Information 139 Reporting of performance measures is not a trivial task. The following steps for developing a robust performance measurement reporting strategy are provided based on guidance from the FHWA Transportation Performance Management (TPM)
From page 140...
... 140 Two important steps are identified for reinforcing performance-based management, as shown in Figure 14. C H A P T E R I V Reinforcing Performance-Based Management Reinforcing Measures Figure 14.
From page 141...
... Reinforcing Performance-Based Management 141 Types of Decisions That Should Be Informed by Performance Measures Level of Support (high, medium, low; blank = not applicable) Safety Mobility Sustainability Level 1: High-Level Decision Makers 1 Making the case for additional investment H H M 2 Reporting on the cost effectiveness of current responses M M H 3 Gaining public and other decision makers' support for program H H M 4 Improving decision making with respect to budgeting and programming funds H Level 2: Statewide/Regional Operations/Maintenance Leads 5 Maintaining adequate winter mobility in the state H 6 Supporting better allocation of funds between regions/districts H H H 7 Managing performance of contracted services H 8 Optimizing material management (balancing available supply and demand)
From page 142...
... 142 Performance Measures in Snow and Ice Control Operations Step 10: Evaluate and Improve Performance measures are not static. As program missions, goals, and objectives change, performance measures may have to be modified as well.
From page 143...
... 143 Adams, T., Wittwer, E., O'Doherty, J., Venner, M., and Schroeckenthaler, K
From page 144...
... 144 Performance Measures in Snow and Ice Control Operations Margiotta, R., Lomax, T., Hallenbeck, M., Dowling, R., Skabardonis, A., and Turner, S

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