A new dual-regime acceleration model was developed to represent the acceleration behaviour of drivers in a platoon of vehicles. Two sets of field data collected by aerial photographic techniques were used to assess the validity of the proposed and existing acceleration models. A single regime acceleration model failed to present the acceleration behaviour of drivers. The field data indicated that at around 13 m/sec the acceleration rate drops. Thus, two different acceleration rates, higher acceleration rate at lower speeds and lower acceleration rate at higher speeds, were used to provide the best fit to the data. This provided realistic acceleration behaviour of drivers in a platoon. The field data sets were collected about 10 years apart. The improvements in acceleration capability of a platoon of vehicles from two different time periods were determined. Improvements in performance of vehicles were quantified using the above mentioned field data. The method of quantification can also be used to predict and model the performance of vehicles currently in use. Inversely, current vehicles can be downgraded to represent vehicles of past years and thus make use of already collected data. Important uses of the dual regime model are in modelling the traffic flow behaviour and designing roadway elements that depend on acceleration behaviour of drivers.
Abstract