Field study and modeling of vehicles’ merging behavior from an acceleration lane to expressway traffic

Vehicles’ merging behavior from an acceleration lane to expressway traffic is complex. Field studies were conducted in Beijing and Jiangsu province in China with a video tape recorder and the Autoscope-2004 image sensing system to explore the vehicles’ merging behavior. The vehicles' merges are found to occur mainly near the middle length of the acceleration lane. Equations associated with exponential distribution are derived to compute the probability of vehicle’s driving distance on the acceleration lane before merging. These equations can model the observed data in the field study with very high value of coefficient of determination. Different traffic flow rates on the expressway are input to the equations to explore the influence on the probability of vehicle's driving distance before merging. It is also found that the traffic flow rate on the expressway has significant influence on the necessary length of the acceleration lane.