Simple platoon advancement: a model of automated vehicle movement at signalised intersections

摘要

The Simple Platoon Advancement (SPA) model describes a conceptual Intelligent Transportation System in which vehicles are progressed through signalised intersections under the automatic control of roadside and in-vehicle infrastructure. The objective is to increase the throughput of vehicles by moving the queue as a closely-spaced platoon on the start-of-green. Comparisons of stopline throughput are made between the SPA model and a valid representation of current road traffic behaviour. The paper contains a description of a basic model—the homogeneous SPA model with constant acceleration—where all vehicles behave the same in terms of their acceleration characteristics, the time headway they desire and the target speed each is trying to reach after passing through the intersection. The acceleration characteristics in question are the rate and the style: that of this model has no smoothing effect and is instantaneously wrought on a vehicle. Though this is somewhat unrealistic for a working system, the constant acceleration model serves as a yardstick for which to check and compare the development of future models. The framework for this model is defined to enable calculations of measurable goals such as stopline throughput for comparison with the EQD model of current road traffic behaviour. In terms of throughput, the homogeneous SPA model shows that even with a very cautious approach using conservative parameter values, the number of vehicles that would pass the stopline of a SPA-equipped intersection is a little more than 150% compared with the throughput found in today's road systems. Reductions in jam spacing increase the throughput still further.