Optimal Corridor Selection for a Road Space Management Strategy: Methodology and Tool

Sushant Sharma

doi:10.1155/2017/6354690

Abstract

Nationwide, there is a growing realization that there are valuable benefits to using the existing roadway facilities to their full potential rather than expanding capacity in a traditional way. Currently, state DOTs are looking for cost-effective transportation solutions to mitigate the growing congestion and increasing funding gaps. Innovative road space management strategies like narrowing of multiple lanes (three or more) and shoulder width to add a lane enhance the utilization while eliminating the costs associated with constructing new lanes. Although this strategy (among many) generally leads to better mobility, identifying optimal corridors is a challenge and may affect the benefits. Further, there is a likelihood that added capacity may provide localized benefits, at the expense of system level performance measures (travel time and crashes) because of the relocation of traffic operational bottlenecks. This paper develops a novel transportation programming and investment decision method to identify optimal corridors for adding capacity in the network by leveraging lane widths. The methodology explicitly takes into consideration the system level benefits and safety. The programming compares two conflicting objectives of system travel time and safety benefits to find an optimal solution.

Highlights

According to a recent report travel delays due to traffic congestion caused drivers to waste more than 3 billion gallons of fuel and kept travelers stuck in their cars for nearly 7 billion extra hours [1] while forty-two percent of America’s major urban highways remain congested [2], costing the economy an estimated $160 billion or $960 per commuter in wasted time and fuel annually
Throughout the US, freeway design standards generally comply with the Green Book in terms of lane width, but the shoulder width usage/recommendation varies from state to state
While literature contributed towards operational impacts of reducing lane and shoulder width to add a new lane, there rarely seems to be a study that attempts to understand the network or system level impacts

Summary

Introduction

According to a recent report travel delays due to traffic congestion caused drivers to waste more than 3 billion gallons of fuel and kept travelers stuck in their cars for nearly 7 billion extra hours [1] while forty-two percent of America’s major urban highways remain congested [2], costing the economy an estimated $160 billion or $960 per commuter in wasted time and fuel annually. This demonstrates the direct impact of roadway congestion on economic productivity and competitiveness. The Highway Capacity Manual (HCM) indicates that median-side lateral clearances that are greater than or equal to 2 ft have little influence on freeway operations [12]

Methods

Results

Discussion

Conclusion