Speed Harmonization and Peak-period Shoulder Use to Manage Urban Freeway Congestion

Abstract

Traffic congestion is an increasing problem in the nation’s urban areas, leading to personal inconvenience, increased pollution, hampered economic productivity, and reduced quality of life. While traffic congestion tends to continuously increase, growth in transportation infrastructure is limited by financial and land availability constraints. This has placed an increasing emphasis on using dynamic traffic management strategies, such as speed harmonization and peak-period shoulder use, to efficiently manage congestion using existing freeway capacity. This project implemented various strategies of variable speed limits and shoulder use and assessed their impact on traffic operations and safety of freeways. These strategies were found to homogenize traffic and create safer driving conditions, but did not increase the throughput of the system. The intelligent transportation system (ITS) devices required to implement these strategies, enforcement issues, potential impediments in their implementations, and a framework for cost-benefit analysis to determine the economic viability are also discussed.