Project Snapshot. More details below.

Staff Responsibility: Stephen J. Andrle

Measures of transportation system performance are integral to demonstrating the need for highway capacity expansion, evaluating alternative solutions, and monitoring performance. To date, agencies have generally had greatest success with operations and maintenance related measures, such as pavement quality, bridge deficiency, and safety; and capacity related measures such as volume-to-capacity ratio, or level-of-service rating. Well-established data collection and analysis techniques have reinforced the use of these and similar measures as tools for decision making.

The public continues to be concerned about the impacts of adding highway capacity and demands even broader analysis. Now measures addressing environmental justice, greenhouse gas emissions, infrastructure vulnerability to climate change, air toxics exposure, consistency with land use and other plans, community cohesion, and visual quality are of interest. Transportation agencies generally do not have well-developed data collection and analysis techniques in these new areas. Even selecting the measures is a matter for public input and debate. Some of the challenges that must be overcome include performance measure design, data collection, target setting, and interpretation and use of results. Better approaches are needed for quantifying transportation system performance in non-traditional areas. The ability to better understand system-level performance in terms of economic, mobility, accessibility, safety, environmental, community, and social considerations leads to more collaborative decision making during system planning and project development.

Performance measures have communication value as well as analytical value because a better collective understanding is achieved of the transportation problem being addressed. Each constituency can see a measure that relates to its concerns, and each constituency can better see the concerns of others. A fundamental principle of SHRP 2 Capacity research is that the right people must be at the table at the right time with the right information. Performance measures that stakeholders help to select that speak to their concerns is a big step toward making the best transportation decision and delivering it with a minimum of delay.

The objective of this project was to develop a performance measurement framework that informs a collaborative decision-making process. The measures reflect mobility, accessibility, economic, safety, environmental, watershed, habitat, community, and social considerations.

The report devotes a chapter to each of the five performance areas, covering for each the background literature, key findings, identification of performance factors, a selection of measures for each factor, and case study references. For example, under the “community cohesion” factor, five measures are suggested: