URBAN FREEWAY CONGESTION: QUANTIFICATION OF THE PROBLEM AND EFFECTIVENESS OF POTENTIAL SOLUTIONS

A major research study of traffic congestion on urban freeways is reported. The study undertook an analysis of the problem, and the Highway Performance Monitoring System (HPMS) was used as the basic source of data. The data were for 1984 and were limited to freeways in urban areas with populations greater than 50,000. The data set consisted of 8,036 sample sections. The data were entered into a microcomputer for computation of travel and congestion statistics. Predictions of future urban freeway congestion statistics were calculated using state-supplied estimates of annual average daily traffic for each sample section in 2005. The analysis of remedial measures is described and includes effectiveness analysis, cost analysis, combined improvement analysis, and the implications of the analyses. The study indicated that demand reduction strategies should be seriously considered when seeking solutions to urban freeway congestion problems. It also indicated the scope and magnitude of existing and predicted urban freeway congestion. The study also provides a first cut at estimating the cost and congestion reduction potential of various options generally available. It is noted that new and innovative improvements must be developed to address the portion of the problem that is currently difficult to treat in a cost-effective manner, and existing solutions must be pursued.