Comparative analysis of macroscopic traffic models for evaluating shockwaves under lane closures on an urban highway using the LWR model

Lane closure due to traffic crashes is a complex phenomenon that negatively affects the operational performance of highways and leads to secondary lane closures. The present study investigates the effects of shockwaves caused by a heavy vehicle run-off-road crash on a three-lane urban highway in Isfahan, Iran. Additionally, the study simulates the effects of lane closures on shockwaves and density using the Lighthill, Whitham, and Richards (LWR) theory and macroscopic traffic flow based on field data. An analysis of traffic flow models revealed that one-lane and two-lane closures reduce maximum flow by 29% and 61%, respectively, compared to normal conditions. The results showed that the minimum relative error (RE) for lane closures is associated with shockwave models based on the Underwood speed-density model, expanded using the Taylor series. Therefore, the shockwave model based on the Underwood model with Taylor series expansion outperforms other models.