Monitoring Urban Freeways in 2003: Current Conditions and Trends from Archived Operations Data

2004Final ReportPDFTech ReportFWHA-HOP-05-018DTFH61-01-C-00182MobilityMonitoringPerformanceTraffic congestionReliabilityData banksFreewaysExpresswaysMobility monitoringPerformance monitoring:Highway congestionReliabilityArchived dataUnited StatesTexasTexas Transportation InstituteCambridge SystematicsUnited States. Federal Highway AdministrationTurner, ShawnMargiotta, RichLomax, TimTexas Transportation InstituteCambridge SystematicsUnited States. Federal Highway Administration. Office of OperationsBattelleUS Transportation CollectionThe Mobility Monitoring Program is an effort by the Federal Highway Administration (FHWA) to track and report traffic congestion and travel reliability on a national scale. The Program uses archived traffic detector data that were originally collected for traffic operations purposes. The Program started in 2001 (with an analysis of 2000 data) in 10 cities. In 2004, the Program has grown to include nearly 30 cities with about 3,000 miles of freeway. The Program tracks three congestion measures (travel time index, percent congested travel, and delay) and two travel reliability measures (buffer index and planning time index). The findings from the most recent analysis of 2003 data are as follows: (1) Average traffic congestion and reliability from 2000 through 2003 appears to have experienced steady decline in numerous cities. (2) In most cities, travel reliability appears to be strongly correlated to traffic congestion. The nature of this relationship varies among cities, but preliminary hypotheses suggest that aggressive freeway operations and management contributes to improved reliability for similar average congestion levels. (3) The approach used in this Program can also be used by State and local agencies. In fact, several agencies already have implemented similar analytical methods and/or performance measures. (4) There are still several issues that, if addressed, could improve the process and results. One of the most important issues to address is improving data quality at the data collection source.77