Knowledge Resources

The Washington State Department of Transportation (WSDOT) found customer-oriented performance measures to be very effective in drawing attention to the benefits associated with its transportation investments and in building credibility for the agency. As part of WSDOT’s efforts to define performance measures for traffic congestion, the agency moved beyond using traditional measures of average travel speeds. The agency added measures focused on travel reliability (e.g., through use of a "buffer index"* to account for non-recurring delay). These measures were developed through coordination between planners and operators, and involve ongoing coordination to track performance. Prior to this effort, non-recurring delay did not receive this systematic consideration.

According to a WSDOT staff person "The Secretary felt that by building the State DOT's accountability, the agency could attract more funding. The Secretary focused on making the case that WSDOT is on top of things. The best way to do that was through operations data because it gets at aspects of the system that the public cares about."

To draw attention to the benefits of travel time reliability, WSDOT's experience provides the following insights:

• Publish a quarterly report on the State's transportation system titled "Measures, Markers, and Mileposts." Also referred to as the Gray Notebook, WSDOT's quarterly report highlights the status of current projects, details where transportation funds are being used, and updates progress on management and operations measures such as incident clearance time and travel information provision.
• Develop goals and objectives that drive performance measures in the Long Range Transportation Plan (LRTP) and reflect the region's vision for its transportation system. Customers (including the general public, freight shippers, and others) are increasingly concerned about operational performance of the transportation system, including the reliability of information about travel conditions that can provide the best travel time, mode, and route.
• Incorporate operational performance measures into the LRTP to provide an avenue for operators and customers to get involved in the planning process. The LRTP can provide better information to customers and stakeholders on the progress being made toward desired goals and objectives, and can, therefore, serve to make long-range plans more real to the public. Moreover, incorporating performance measures helps to ensure that regional transportation system management and operations programs receive adequate attention in prioritization of projects for funding.

This lesson portrays the experience of the WSDOT in including operational performance measures in the development of long range transportation plans. The benefits include helping planners focus on the day-to-day experiences of transportation system users. This collaboration between operations and planning personnel recognizes the significant impact that these measures have in improving the performance of the transportation system. WSDOT achieved their goals of improving productivity, efficiency, and customer satisfaction by providing metrics for issues such as incident-related delay and reliability, which are important customer issues that have not traditionally been included as performance measures in past long range planning efforts.

*The Buffer Index expresses the amount of extra time a traveler must allot for each trip in order to be on time 95 percent of the time. As an index, this measure is useful for comparisons regardless of travel time and trip distance. The measure can also be presented in actual minutes of extra time required in cases where one wishes to evaluate reliability for a particular trip. Typically, the index is calculated for each road segment, and a weighted average is calculated using vehicle-miles of travel as the weighting factor.