Impact of light rail on traffic congestion in Denver

Abstract

Among the reasons the light rail system in Denver has been built is to reduce traffic congestion. A temporal and spatial analysis of Vehicle Miles Traveled (VMT) data from 1992 to 2008 on the highways in Denver has been conducted to determine if that objective has been fulfilled after the initial light rail service began in 1994. Temporal analysis provides an insight into the changes in the level of highway traffic before and after the opening of three segments (Central, Southwest, and Southeast Corridors) of the light rail system. This part of the analysis also compares the traffic levels of highways affected by light rail with those not affected by light rail. Spatial analysis examines whether the changes have taken place uniformly throughout all the highways, or whether they have been concentrated on particular highways. Results indicate that light rail has reduced level of traffic along some of the adjacent highways for a short period of time. Overall, the three light rail corridors in operation have succeeded in lowering the rate of increase in the level of traffic on highways within the rail transit influence zone as compared to highways outside the influence zone.