Influences of Cross-Sectional Design Elements at Urban Arterial Driveway Locations

This paper presents a study on the influences of select cross-sectional design elements—specifically median configurations and bicycle lanes—and their impact on crash severity and type as well as the associated driver gap acceptance for turning maneuvers at midblock driveway locations on urban arterials. The primary goal of this research is to better understand how median and bicycle lane configurations can influence safety and operations at driveway locations. The authors used crash data, traffic data, and roadway information from driveway locations in Oregon, Arkansas, and Oklahoma. The data were supplemented with digital videos from field studies of the sites. These traffic videos helped to better understand how road features and traffic influenced driver behavior at selected urban arterial driveway locations. Gap acceptance studies were conducted to determine critical gaps for driveway locations at arterial roads with and without bicycle lanes. Four critical gap analysis methods were evaluated to estimate driveway operations and noted potential procedural biases associated with two of the techniques. The paper describes these field studies and summarizes how gap acceptance varied at different arterial driveway locations. Simulation analysis in CORSIM (Version 6.3) examined the influence of median type, traffic volume, and access density on traffic operational performance.