Determination of Adequate Distance for Driveway Corner Clearance

Abstract

Direct vehicle access at site is usually restricted in situations where the driveway corner clearance (DCC) is designated, as per the District Unit Planning Guidelines. Currently, no clear installation standard for the DCC in Korea exists; thus, vehicles are allowed access regardless of the clearance between the driveway and the intersection. When driveways are located adjacent to the intersection, frequent conflicts between vehicles on minor and major roads occur. This results in problems with traffic communication and safety, necessitating a reasonable design. Therefore, in this study, DCCs were classified into upstream driveway corner clearance (UDCC) and downstream driveway corner clearance (DDCC), and algorithms and scenarios for calculating the appropriate DCC distance were proposed. DDCC was calculated from the traffic volume entering the rightmost lane of the DDCC from among the 12 intersection directions by applying optimized signal phase sequence and car-following theory. The DDCC results demonstrated that at least one vehicle in the driveway can exit to the rightmost lane on the roadway at 9.22 m. Two vehicles can exit at 32.15 m, and three vehicles can exit at 67.54 m. UDCC was calculated by considering its geometry, the traffic volume, queue length, and the 8.45 m additional distance from the driveway. Therefore, as traffic volume increased, the queue length and queue clearance time of the queue increased. The calculated DCC distance proposed in this study can contribute to establishing design standards in the future when establishing guidelines for district unit planning.