Washington State

Overview of TIM Program

Incident Response (IR) is the Washington State Department of Transportation’s (WSDOT) traffic incident management program. The mission of IR is to clear to assist drivers, clear incidents, provide traffic control to assist first responders, and keep the roads in Washington operating efficiently. IR has teams that are trained to support first responders at traffic incidents that occur within WSDOT’s coverage areas. Per Washington State law, IR teams are defined as first responders, and their trucks are equipped with lights and sirens accordingly. IR maintains over 55 vehicles statewide, which respond to approximately 13,000+ incidents quarterly on state roads, including interstate highways. IR teams are active in Seattle 24 hours, 7 days per week. Coverage in other regions is more limited and driven by resources available and where incidents are most likely to impact mobility. The WSDOT operates six traffic management centers (TMCs), one in each region. Each region’s TMC is responsible for managing all of the state highways in that region. All six of the TMCs operate around the clock and are in constant communication with the IR teams in the field.

Data Collection and Management

WSDOT is the lead agency in the state of Washington for the collection and reporting of TIM performance measures, and it actively collects data in support of two of the national TIM performance measures, incident clearance time (ICT) and roadway clearance time (RCT). The primary mechanism for collecting the data is via the incident reports completed by the IR crew members (a WSDOT incident response form is shown in Figure 1).[1] The data elements needed to calculate RCT and ICT – “incident start time,” “time all lanes open,” and “time cleared” – are circled in red on the form in Figure 1. Other data elements that could be used in TIM performance analyses – “number of vehicles involved,” “work zone,” “reason for response,” and “additional agencies/units involved” – are circled in blue.

Using laptop computers in their trucks, IR crew members enter incident data into an electronic incident report. The incident data are stored on the laptops during the work shifts. After each shift, the stored data are uploaded to a secured DOT server via WSDOT networks into the Washington Incident Tracking System (WITS). WITS is a centralized statewide database that was developed in-house. WITS has three basic functions: an electronic data collection system, a database management system (DBMS), and a query/reporting capability and management decision making tool. WITS tracks incident response data daily, and archive data are available from January 2002.[2]

Figure 1. Traffic Incident Management Performance Data Elements on the WSDOT Incident Report

Figure 1. Traffic Incident Management Performance Data Elements on the WSDOT Incident Report

Performance Analysis and Reporting

Summary results from analyses on data in WITS are reported in various forms on various recurring schedules to management, administration, and the public. The information from these reports is often used in transportation studies and in management and system performance decisions. Tracking and reporting performance as such allows WSDOT to effectively manage system assets and investments, optimize existing system capacity, promote sustainable practices, support a culture of innovation, strengthen partnerships, and improve communication with users.[3]

More specifically, WSDOT uses the WITS data archive to conduct short-term trend analyses to monitor overall program performance. Average RCTs and ICTs are reported in the Gray Notebook, WSDOT’s quarterly performance report on transportation systems, programs, and department management, which is WSDOT’s primary tool for reporting performance and demonstrating accountability. Figure 2 shows one example from the September 30, 2015 Gray Notebook, which reports current average ICTs and compares them to the previous period ICTs, as well as the five-quarter trend. The primary reason that WSDOT has for comparing these measures is to track congestion relief and improved freight mobility.[4]

Figure 2. Extract from WSDOT’s Gray Notebook – Statewide Transportation Policy Goals (September 30, 2015)Figure 2. Extract from WSDOT’s Gray Notebook – Statewide Transportation Policy Goals (September 30, 2015)

Average RCTs and ICTs are also reported in WSDOT’s annual Corridor Capacity Report. Figure 3 shows a graph extracted from the 2015 Corridor Capacity Report.[5] This graph shows the number of IR team responses and the average ICTs annually from 2010 to 2014. The graph indicates that both the number of responses and the average ICTs have been relatively consistent over this 5-year period, and that even with slight increases in 2014 in the number of responses, the average ICT decreased slightly.

Figure 3. Extract from WSDOT’s 2015 Corridor Capacity Report – Incident Response Data

Figure 3. Extract from WSDOT’s 2015 Corridor Capacity Report – Incident Response Data

Figure 4 shows the results from an analysis of WITS data examining and comparing number of responses and the average ICTs by incident type and injury severity for the third quarters of 2002 and 2004.[6] Incident types include collisions, non-collision blocking incidents (i.e., blocking disabled, debris blocking traffic), and non-collision/non-blocking incidents (i.e., disabled vehicle, abandoned vehicle). Injury severity includes fatality, injury, and non-injury collisions/incidents. This graph is a good example of the benefit of breaking down the analysis for a closer look at performance (average ICTs) by incident type and injury severity as opposed to using only overall aggregate averages. The graph indicates that, even as the number of responses increased quite significantly between 2002 (before the IR program expansion) and 2004 (after the IR program expansion), average ICTs decreased across nearly all of the incident categories. A similar graph is shown in Figure 5 for number of responses and average ICTs by roadway and direction between January 2003 and September 2004.[7]

Figure 4. WSDOT TIM Performance by Incident Type and Injury Severity

Figure 4. WSDOT TIM Performance by Incident Type and Injury Severity

 

wsdot_tim_performance

 

Figure 5. WSDOT TIM Performance by Clearance Time and Number of Responses 

Benefits of TIM Performance Measurement

Having data on the TIM performance measures has helped WSDOT show trends and progress in its IR Program. The data have been used multiple times to justify the increased expansion of the IR program to the legislature. Since its beginning in 1999, the IR Program has been expanded three times, and the decisions have been driven by the data. WSDOT is accountable to the legislature for the funding for the program overall, as well as for program expansions. WSDOT uses performance analytics to describe the benefits of the program to the legislature. Figure 6 shows the quarterly average ICTs over a 3-year period including two quarters before and ten quarters after the expansion of the IR program in 2002. The trend lines show that, while the number of responses increased dramatically after the expansion and continued to increase over the following two years, the clearance times dropped dramatically after expansion of the program and held steady despite the increasing number of responses.

Figure 6. Washington State Department of Transportation Analysis of Trends Using the Statewide Incident Tracking System Data

Figure 6. Washington State Department of Transportation Analysis of Trends Using the Statewide Incident Tracking System Data

As an agency, the WSDOT is very focused on getting the most out of its existing infrastructure and resources, and understanding performance of the system is key to accomplishing this objective. This philosophy drives the agency, as well as where it should be investing money. As such, the WSDOT is focused on understanding the impacts of congestion and using available strategies and tools, such as the IR program, to address certain problems. One of the ways in which the WSDOT demonstrates the value of the IR program is by calculating the economic benefits of the program. Figure 7 was extracted from WSDOT’s 2015 Corridor Capacity Report.[8] As noted, economic benefits are the sum of benefits from saved time, gasoline, and avoided secondary crashes due to the IR teams’ proactive work. WSDOT’s methodologies for calculating economic benefits are fully described in WSDOT’s Handbook for Corridor Capacity Evaluation.[9] These monetized benefits are then compared to the costs of the program, and a benefit/cost analysis on the response to incidents is conducted every year. This information is also used in the justification to legislature of the IR program expansions.

Figure 7. Extract from WSDOT’s 2015 Corridor Capacity Report – Economic Impacts of IR Program

Figure 7. Extract from WSDOT’s 2015 Corridor Capacity Report – Economic Impacts of IR Program

[1] Washington State DOT, Incident Report.
[2] Murthy, G., How WSDOT Incident Tracking System Leverages Archived Data, Presentation to ITS America Annual Meeting, May 2, 2005.
[3] Washington State DOT, The Gray Notebook: Quarter ending September 30, 2015, November 2015, http://wsdot.wa.gov/publications/fulltext/graynotebook/Sep15.pdf.
[4] Washington State DOT, The Gray Notebook: Quarter ending September 30, 2015, November 2015, http://wsdot.wa.gov/publications/fulltext/graynotebook/Sep15.pdf.
[5] Washington State DOT, The 2015 Corridor Capacity Report: The 14th edition of the annual Congestion Report, October 2015, http://wsdot.wa.gov/publications/fulltext/graynotebook/CCR15.pdf.
[6] Murthy, G., How WSDOT Incident Tracking System Leverages Archived Data, Presentation to ITS America Annual Meeting, May 2, 2005.
[7] Murthy, G., How WSDOT Incident Tracking System Leverages Archived Data, Presentation to ITS America Annual Meeting, May 2, 2005.
[8] Washington State DOT, The 2015 Corridor Capacity Report: The 14th edition of the annual Congestion Report, October 2015, http://wsdot.wa.gov/publications/fulltext/graynotebook/CCR15.pdf.
[9] Washington State DOT, WSDOT’s Handbook for Corridor Capacity Evaluation: 1st edition, October 2014, http://wsdot.wa.gov/publications/fulltext/graynotebook/CCR14_methodology.pdf.