Comparing Perceptions and Measures of Congestion (UTCM 11-00-72)

People's perception of congestion and the actual measured congestion do not always agree. Measured congestion relates to the delay resulting from field measurements of traffic volume, speed, and travel time. People's perception of congestion can be influenced by relative year to year growth in congestion, improved or new transportation infrastructure, and societal attitudes on transportation. IBM publishes an annual study on the attitudes of commuters from across the world on their daily travel (known as the Commuter Pain Survey). The Texas A&M Transportation Institute (TTI) publishes an annual Urban Mobility Report that measures urban mobility based on public and private traffic data for highways, streets, and transit. This research attempts to connect the relationships between perceived congestion as determined by IBM's Commuter Pain Survey results and measured congestion from the Urban Mobility Report (UMR) in 10 cities across the United States. The raw Pain Index values (the unadjusted index values based entirely on survey responses) had higher correlation with TTI-based measures than the published Pain Index. The Raw Pain Index was found to correspond to a composite model of two of the four core UMR measures examined-the Travel Time Index and the Roadway Congestion Index. This study also examines the correlation of measured congestion between the UMR and two measures of the INRIX National Traffic Scorecard. The Travel Time Tax (T³) and the Worst Hour T³ were found to correspond to a model of the Travel Time Index of the UMR. The Travel Time Tax correlates especially well with the Travel Time Index.