On a Variant of the Mobile Observer Method

The mobile observer method has been used by traffic engineers since the middle of the last century to estimate traffic velocity, flow and density. Although simple and intuitive, the method suffers from two major issues. First, the vehicle must traverse a given road segment both in the direction of the traffic whose parameters are of interest and also in the opposite direction, essentially driving in a loop. Second, to get accurate results, several runs must be taken and the results aggregated. Our variant utilizes the communication capabilities in present-day vehicles to mitigate both these issues, thus enabling faster and more accurate traffic maps and traffic routing applications. Extensive simulation results have confirmed that our variant of the mobile observer method is comparable in accuracy with the stationary observer method even at lower flow rates.