Research on the basis of the setting of the dedicated left-turn lane at the two-phase intersection

Abstract

In two-phase intersections, there is serious conflict between straight-going vehicles and left-turning vehicles. It is particularly important to set up a dedicated left-turn lane reasonably. In order to provide the conditions for setting the dedicated left-turn lane, this article is based on the theory of dispersible gaps to determine the arrival rate and turn left. The vehicle ratio is a variable, and the delay of the two-phase left turn is obtained. Respectively established the rotation organization mode in the case of Erlang distribution arrival. And take the geometric design and signal control of a certain intersection in Xi'an as an example for delay analysis. The calculation results show that: the total delay increases with the increase in the arrival rate and the proportion of left-turning vehicles; the straight-left shared lane is suitable for smaller traffic demand, and the left-turn dedicated lane is suitable for larger traffic demand. When the arrival rate is not greater than 0.12pcu/s or arrival rate is 0.12~0.24pcu/s and the ratio of left-turning vehicles is not greater than 0.2, it is recommended to set up a straight-left shared lane; or the arrival rate is 0.24~0.37pcu/s and the ratio of left-turning vehicles does not exceed 0.1, it is recommended to set up a straight-left shared lane too. When the arrival rate is When it is 0.12~0.24 and the ratio of left-turning vehicles is greater than 0.2 or the arrival rate is greater than 0.37pcu/s, it is recommended to set up a dedicated left-turn lane.