Micro-simulation modelling of congestion due to lane closures

Incident clearance and road work often require the closure of one or more of the available lanes on a highway. A lane-closure causes a significant capacity reduction, which often leads to heavy congestion. Simulation of congestion events due to lane - closures is relevant both for traffic and infrastructure management. This is especially valid when trucks are involved and they concentrate on bridges or in tunnels, thus generating critical situation s for loading and safety. A better understanding of the effects of lane closures requires a realistic simulation of the merging manoeuvre of vehicles occurring in the proximity of the lane closure. Micro-simulation allows for the motion of individual vehic les and it is therefore a suitable tool for studying traffic merging. In this paper, a micro-simulation tool made up of a car-following model and a lane-changing model is used for simulating a lane closure on a two-lane one direction stretch of road. The effects on traffic are studied, in terms of average speed, lane change rates, and truck distribution. It is found that the lane-changing model requires an appropriate parameter calibration when applied to lane-closures. These parameters are quite different from the ones reported in literature. An alternative means of causing congestion is also tested and it is found that it can replicate the overall congestion features upstream the closure. However, there are some differences about details of the traffic features