Safety and Economic Impacts of Converting Two-Way Frontage Roads to One-Way: Methodology and Findings

In the research documented here, researchers develop information to communicate the safety and economic impacts of converting frontage roads from two-way to one-way. Researchers studied five locations in Texas where frontage roads were converted from two-way operation to one-way operation. Researchers identified a comparison site in Texas that remained two-way for comparison to four of the treatment (conversion) sites. Researchers developed accident modification factors (AMFs) related to frontage road conversion segments that roadway designers can use to guide frontage road conversion project planning. Researchers developed AMFs based on non-property-damage-only (non-PDO) crashes for segments and interchange intersections. Researchers developed 12 AMFs and provide confidence intervals around the estimates. Researchers describe how the AMFs were developed, associated caveats, and how to apply the AMFs. Researchers also document the process used to build the safety database from electronic data-sets and printed crash reports. Finally, researchers provide recommendations to facilitate and expedite future crash analyses. Researchers attempted to investigate the economic impacts of frontage road conversion by analyzing gross sales data, appraisal data, employment data, and surveys of business owners/managers and customers. Only the appraisal data and survey information were at the parcel level along the corridors and survey sample size was limited.