Live Stop Controlled Intersection Data Collection PDF Download

This report presents the study of minor street drivers' gap and lag acceptance and rejection at a non-standard stop-controlled T-intersection. In this context, non-standard stop-controlled intersections are those at which priority right-of-way is given to a left-turning traffic stream. The arrival and departure times of all vehicles entering the intersection were collected with a traffic classifier and video camera. Lag/gap acceptance and rejection values were found for several specific movement combinations. The resulting critical lag and gap values varied over a wide range, depending upon the method used to derive them and the particular movement pattern being considered. Values ranged from 1.8 to 9.0 seconds, with the majority of the critical gap values higher than the critical lag values for the same movement. The lower lag/gap values were from a movement pair associated with non-standard control: drivers stopped to wait on the oncoming traffic stream having the right-of-way often choose to proceed when oncoming vehicles are close, assuming that if an oncoming vehicle has not reduced its speed by the time it is close to the intersection, it will probably proceed through and not turn left. At the intersection studied, this non-standard stop-controlled pattern sometimes caused confusion among drivers and excessive delay on minor street approaches during high traffic volume periods.