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Title: Access Control Design on Highway Interchanges
Project No.: 80596
Target Date: 01/31/2008
Abstract: The Access Control Agreement for Interstate Interchanges in Va. between VDOT and the FHWA, dated 4/28/04, sets the minimum length of access control on crossroads adjacent to interstate ramps as 100 ft. in urban areas and 300 ft in rural areas, measured from the terminal of the ramp. It is not clear how these distances were arrrived at given that there are numerous factors such as the potential impact of the access on signal progression if the ramp is included in a coordinated signal system, the number of other intersections and driveways in the vicinity of the interchange, the type and intensity of land use adjacent to the crossroad, and the impact of the access on traffic operations and safety that need to be considered. This project will assess the propriety of the 100ft. and 300ft. requirements and the operational impacts of varying access lengths. It will also synthesize the state of the practice in other DOTs, and will yield guidelines for VDOT to use to designate access breaks. 

     Hesham Rakha