Modeling Speed Adjustment Behavior of Merging Vehicles at Urban Expressway Merging Sections

This paper modeled speed adjustment behavior of merging vehicles by using video data collected at two merging sections on urban expressway in Nagoya City, Japan. The results showed that the longer acceleration lane results in a higher acceleration rate of merging vehicles. And the denser mainline traffic causes a lower that of merging vehicles. In addition, the leading and following time to collision (TTCL and TTCF) were adopted as variables. It is found that if TTCL is negative, merging vehicles increase their acceleration rate. By contrast, if TTCL becomes positive and the collision can happen, merging vehicles tend to reduce acceleration rate to avoid the collision with leading mainline vehicles. In case of TTCF, the positive signs of coefficients indicate that when following mainline vehicles run faster than merging vehicles, they increase their acceleration rate to avoid collision with following mainline vehicles. Furthermore, the validation results suggest a promising applicability of the developed models.