Time Headway analysis on urban roads of the city of Marrakesh

Vehicular Time Headway or Inter-arrival time is an important parameter in traffic flow theory. It has a major effect on traffic simulation especially in the traffic generation process. Most of the previous research on Time Headway modeling have focused on homogeneous traffic, on uninterrupted urban roads, freeways or highways. The situation in Marrakesh is very different where traffic is heterogeneous and intersections are close especially signalized ones in the center of the city. This paper proposes a study of Time Headway on four urban roads with heterogeneous traffic conditions, interrupted by a signalized intersection. A sampling approach is used taking into consideration the signal plan of the preceding intersection. Time Headway samples are then compared to theoretical models used in literature adding also a Paretian model (Pareto type IV) which was discussed in the past as a potential candidate. The study shows that TH distribution in these roads is different from the usually studied roads which is why some of the common models are rejected compared to Pareto type IV that fits well all the TH samples representing different traffic flow levels.