Extensions of theoretical capacity models to account for special conditions

摘要

The computational procedures used to analyze two-waystop-controlled intersections were extended in the NationalCooperative Highway Research Project 3-46 to account for a number ofeffects commonly observed at actual unsignalized intersections. Thispaper presents theoretical extensions that can account for commonlyobserved phenomena, such as two-stage gap acceptance when medianstorage is available, right-turn "sneakers" at flared minor-streetapproaches, non-random arrivals caused by upstream signals, impedancedue to pedestrian crossings, and delay to major-street throughvehicles using shared left-turn and through lanes. The individualeffects are then combined into an analytical framework suitable forinclusion in the Unsignalized intersections procedures of the 1997"Highway Capacity Manual".