Safety and Economic Impacts of Converting Two-Way Frontage Roads to One-Way Operation

In some states (e.g., Texas), frontage roads have been a design solution for providing access along rural freeways and access-controlled principal arterials. In rural and lesser-developed urban areas, the frontage roads are usually operated as two-way facilities because of relatively long distances between interchanges. As areas become more urban and the adjacent land is developed, traffic volumes increase, and as interchange spacing decreases, it becomes desirable to convert the frontage roads to one-way operation. There is a need to objectify safety impacts of frontage road conversion, and business and property owners are often concerned with economic impacts related to access, business activity, and property values. Recognizing these needs and concerns, the Texas Department of Transportation contracted with the Texas A&M Transportation Institute to investigate the safety and economic impacts of converting two-way frontage roads to one way. Researchers investigated eight sites throughout Texas: both conversion sites and comparison sites that remained two way. Researchers developed 12 crash modification factors by crash severity and crash type for frontage road conversion. A sample application is provided in this paper. To assess economic impacts, researchers obtained parcel-level appraisal data and found overall increases in appraised values. Researchers surveyed business owners and managers and customers. Researchers found that business owners and managers are typically concerned with access, gross sales, and ramp and interchange locations and spacing. Finally, researchers identified lessons learned with the crash data for those performing safety analyses.