Method for Selecting the Vehicles That Can Enter a Street Network to Maintain the Speed on Links above a Speed Threshold

Abstract

The introduced method is a proposal for detecting spaces (links) and times (90 s periods) where the average speed is below the desirable, and for selecting vehicles in those spaces and times so that vehicles are systematically and gradually reduced from one simulation to another until we get a simulation presenting the desirable average speed in all space and time. With our method can be detected the specific vehicles that can enter a street network so that the average speed on the network’ links be always greater than a speed threshold. The speed on a segment is calculated from two perspectives: (1) the general speed (vg), calculated with measurements and estimates, used to estimate the links’ travel times for selecting the vehicles routes, (2) the particular speed (vp), calculated without estimates and for segments with traffic light only with measurements performed during an interval of the green time, used to identify links and periods of unacceptable (low) speed. We test our method with different origin-destination (OD) tables, for each OD table we obtain the number of vehicles that can enter the network in 1 h so all links and periods present acceptable speed. Another result was, for each link, the change of the average (and of the standard deviation) of VG (the vector containing the vg of each period) between the final (after our method) and initial (the traffic conditions without our method) simulations, therefore the percentages of the links presenting a convenient change were evidenced. We did the same with VP (the vp of each period).