In this report a procedure is presented for estimating the current length of a queue on a road section from monitoring data based on the travel time over and the number of vehicles on a road section. Both quantities constitute the boundary conditions with which the speed pattern and the density pattern of the traffic on a road section have to comply. In principle, the queue length estimator can be applied to occurring traffic conditions and road section geometries. A distinction has been made between three different traffic situations on a road section with an on and off ramp between the entrance and the exit measuring site. These three traffic conditions differ in the location of the queue in relation to the location of of the queue in relation to the location of the measuring sites. The most complex traffic condition concerning the queue length estimator is the one according to which the queue is located between the entrance and the exit measuring site. The most straightforward situation is the one according to which the queue has extended over both the entrance and the exit measuring site. Numeric examples with the designed queue length estimator show promising estimation results, which usually comply with the accuracy of 1 kilometre that has been strived for.
Abstract