Congestion is probably the main problem in highways, not only in the Netherlands, but worldwide as well. The reasons it occurs vary from case to case; high demand disproportionate to the infrastructure, accidents or frequent lane changes. The latter, and more specifically merging at on-ramps, will be further analysed in this project.
Merging at on-ramps can cause disruptions to the traffic flow. Merging behaviour differs from driver to driver; others merge too soon, others too late. Merging is based on gap acceptance, which is the gap between two vehicles already on the highway that is accepted by the merging vehicle; others prefer larger gaps while others, especially when being at the end of the merging lane, choose smaller gaps. Merging also results in the relaxation phenomenon. During merging, drivers accept smaller gaps, in general, which they later want to bring back to the initial sizes. This is why merging is not only the lane change itself. It starts before and ends after the merging point.
At the moment, merging is performed manually. The assistance of Intelligent Transportation Systems (ITS), both in-vehicle and outside can improve merging behaviour. The ITS can provide the drivers information of their surrounding environment, as well as provide advice for their next moves. In that way, the congestion effects could be possibly minimised resulting in smoother and less disrupted traffic flow. The data that will be used are provided by loops installed on the A20 highway and give flows and mean speeds per loop. More specifically, the data are from the weaving section between the junction with the A13 and the junction with the N471 (roundabout), as well as the parts before and after this section, resulting in a segment of almost 3 kilometres.