Analysis and Assessment of Freeway Weaving Segments in Mosul City, Iraq

The purpose of this work is to compare and assess the accuracy and effectiveness of weaving segment analysis methodologies offered in the last three current editions of the Highway Capacity Manual (HCM). The study area consists of three major weaving segments on the main urban freeway in Mosul City. Traffic data for this work were collected using video recordings. Two stages were created, with six weekdays of 12 hours of daily traffic operations videotaped at each location to cover a wide range of traffic flow characteristics. The GoodVision Software was used to assess if the HCM methodology can effectively predict the behavior of weaving sections. The results, comparing estimated values from three methodologies with observed values for weaving and non-weaving speed and density under peak-hour normal daily traffic conditions, show the relative validity of HCM 2000. The work revealed that traffic congestion and problems on the freeway section downstream of the weaving segment had a noticeable influence on non-weaving speed and density, as well as the level of service and weaving performance. As a result, the work recommended future research to incorporate this influence into the HCM methodology.