Modelling motorway merge: The current practice in the UK and towards establishing general principles

Motorway merging has been regarded as a major source of conflicts and congestion, but has long been recognised as an area in which modelling has been relatively weak. The current traffic models represent the traffic operations at a merge are based on gap-acceptance approach, with the merging traffic giving-way to traffic on the mainline carriageway and imposing little or no delay to the mainline traffic. The results tend to overestimate delays to the merging traffic, and underestimate delays and interruptions to the mainline traffic.