Improving Transportation Systems Management and Operations – Capability Maturity Model Workshop White Paper – Performance Measurement
6. Best Practice Examples
As noted above, most CMM workshop sites have undertaken some degree of TSM&O Performance Measurement. Most of the activities are rudimentary, however, focusing on producing, but not fully utilizing, performance measures. Most of the TSM&O Performance Measurement production focused on incident data, primarily because these data are simple, not too voluminous, and collected directly by TSM&O units or easily obtained through emergency responder CAD systems. That said, several states had advanced beyond their peers and serve as guideposts for others.
Georgia DOT (GDOT). GDOT has a relatively comprehensive program that encompassed several (but not all) Performance Measurement functions. GDOT has a long history of publishing weekly and monthly reports on TSM&O activities. The focus of the reporting is TIM characteristics but other aspects also are covered, including 511 calls, GDOT traveler information web site “hits,” and device health. They have used the incident performance data to adjust service patrol intensity and duration in corridors. GDOT has not yet integrated these output-related measures with outcome (travel time-based) measures, but they have used travel time data from their detectors to identify bottlenecks and to locate potential locations for ramp metering. They also are using commercially provided travel time data to fill in gaps and as a basis for their Regional Traffic Operations Program (RTOP), which is heavily oriented to signalized arterials. Perhaps the Performance Measurement area where GDOT is the strongest is evaluations. Whenever GDOT implements a new TSM&O strategy, the agency evaluates its effectiveness. These evaluations include benefits assessments for use in justifying TSM&O programs. GDOT’s extensive and highly maintained detector network enables these evaluations to take place. GDOT has also developed an agencywide performance dashboard. It includes a TSM&O measure (service patrol response time) and summary outcome measures for congestion. The front page of the dashboard allows users to drill down to obtain details regarding each top-level measure.
Maryland SHA (MSHA). MSHA has a long-standing TSM&O Performance Measurement program (currently limited to freeways). The program has overcome many of the obstacles faced by agencies, but the major limitation was incorporating performance measures into investment decisions at multiple levels, which, as pointed out above, is a particularly difficult problem to rectify both technically and institutionally. MSHA historically had a very strong output-level Performance Measurement program in the form of its CHART program, which has published annual performance reports for over a decade. The CHART reports included an assessment of the benefits of CHART activities, but this assessment was based on modeling rather than measurement. MSHA now includes outcome measures in its reporting, primarily based on vehicle probe data obtained through the I‑95 Corridor Coalition. The Annual Mobility Report includes both outcome congestion measures and a separate section on TIM performance. Congestion performance reporting had been limited to freeways but is being expanded to include signalized arterials. The same data are used to inform discussions with the State legislature on funding, a good example of a data-driven process.
Washington State DOT (WSDOT). From an agencywide perspective, WSDOT has been a national leader in Performance Measurement for many years. Its Gray Notebook is often cited as the best example of performance reporting done by State DOTs. In general, Performance Measurement data are effectively utilized in programming and long-term planning at WSDOT. The TSM&O program has successfully used operational outcome data to secure more funding for additional TSM&O projects. WSDOT also has started to set performance targets for many activities, such as incident clearance.
Despite the presence of the exemplary Gray Notebook and other positive aspects of the Performance Measurement program, however, the TSM&O Performance Measurement program faces challenges. Workshop participants’ assessment of the program was better than the average of other workshops, but some noted that performance measures were not substantially integrated into the decisionmaking process (a common theme among all workshops and the most difficult barrier to overcome). No set of common performance measures exists for characterizing TSM&O outcomes. Tactical decisions use some Performance Measurement data, but some systems and processes could more effectively utilize the available data. The linkage between the performance information in the Gray Notebook and decisions about specific investments is tenuous, reflecting a need to go beyond performance reporting to a fully integrated Performance Measurement program.
