The opening length and influencing factors were studied aiming at the traffic of the two lanes at median opening section in expressway reconstruction and extension work zones. A theoretical calculation model of the median opening length is established, the opening section length in different limited speed, the width of median and cross slope are put forward based on the analysis of vehicle running characteristics in the two lanes at median opening section. Simulation method are used to analyze the traffic characteristics in different opening section lengths, including vehicle speed, capacity, speed limit compliance rate and other indicators, the suggestion values of the opening section length and capacity in different design speeds are put forward. Accident form in the work zones are analyzed, the length of the opening section transition area is obtained. TTC (time to collision) was used to evaluate the safety of the opening section, the rear-end collision in different opening lengths are obtained. Simulation results show that the opening section length is in good agreement with the theoretical calculation results, and the operation is good in safety.

CICTP