An inexpensive technical solution for studying vehicle separations within real traffic flows using on-board sensors
Quantifying the separation between vehicles, both laterally and longitudinally, is an important step to understanding some crash events. Examples include, crashes that occur during the various phases of overtaking manoeuvres on high speed roads (pull out, pass, pull in) or where vehicles are passing bicycles on an adjacent travel path. The paper investigates a new option for measuring separation distance using inexpensive LASER distance measuring (LIDAR) devices. Six LIDAR devices were fitted to a vehicle and the accuracy of measurements to another vehicle during an overtaking manoeuvre were evaluated with off-the-shelf differential GPS technology. Data from the LIDAR devices was also used to calculate the passing speed and length of the overtaking vehicle, and the accuracy of these calculations was evaluated. Preliminary results show that the setup delivers results that are acceptable up to distances of 50 meters and at passing speeds up to 20 km/h. This inexpensive solution will facilitate research where separation distance in real traffic flow is an important consideration. Effective use of the technology should take into account possible weaknesses such as inaccurate device positioning and the potential for spurious data.