Study on the Length of Median Opening in Expressway Reconstruction and Extension Work Zones

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. Based on the analysis of vehicle running characteristics in the two lanes at median opening section, a theoretical calculation model is established and the opening section length in different speeds, the width of median and cross slope are put forward. The suggestion values of the opening section length and capacity in different design speeds are put forward using simulation method. Accident form in the work zones are analyzed, the length of the opening section transition area is obtained. TTC 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.