Recent observations at signalised intersections suggest that the total traffic delay at an intersection might be reduced if the approaching vehicle platoons on the major road were allowed to pass through the intersection at the expense of a reasonably prolonged delay of the few vehicles on the minor road. This study investigates vehicle platoon characteristics and develops control logic for timing actuated traffic signals in terms of the presence of vehicle platoons. To effectively analyse traffic flows in terms of vehicle platoons, the following variables were measured and analysed to capture the characteristics of vehicle platoon movements: platoon size,headway, speed, and inter-arrival time. In addition, the critical headway of 2.5 seconds was determined to distinguish platooned vehicles from non-platooned vehicles. Equations were derived to determine the appropriate locations of platoon detectors. Through statistical analyses, the appropriate mathematical distributions of the vehicle platoon variables were determined. Findings showed that the platoon size follows the negative exponential distribution, the platoon headway has normal distribution, the platoon inter-arrival time fits the lognormal distribution, and the platoon speed suits the normal distribution. The statistics of the key platoon variables at different traffic flow levels were computed based on the recorded traffic flow data and regression equations between various platoon-related quantities were developed.
Abstract