详情

原文传递 Left-Turn Lanes at Unsignalized Median Openings.

题名：	Left-Turn Lanes at Unsignalized Median Openings.
作者：	Chen, X.; Lu, Y.; Qi, Y.; Wang, Y.
关键词：	Access Control; Arterial Highways; Deceleration; Intersections; Left Turn Lanes; Medians; Performance Evaluation; Storage Length; Traffic Control; Traffic Safety; Travel Delay; Turning Lanes; Urban Ar
摘要：	Due to the frequent presence of median openings in urban arterial settings, the requirements for the deceleration and storage of turning vehicles (e.g. AASHTO Green Book) often exceed the available length between two adjacent openings which leaves traffic engineers having to decide whether left-turn lanes, shorter than the standards, can be used or not. The goal of this research is to investigate the minimum required length for the left-turn lanes at the unsignalized median openings, and study the safety and operational impacts of such left-turn lanes with substandard lengths. To achieve this goal, researchers will: 1) synthesize existing related research; 2) develop models for storage lengths at unsignalized median openings; 3) develop models for estimating the delays caused by substandard deceleration lengths and the resulting excessive deceleration on main travel lanes; and 4) analyze safety impacts of substandard median left-turn lanes. The results of this study lead to following key findings: 1) at the operational impacts perspective--if a substandard length left-turn lane can accommodate the necessary storage length and the deceleration length assuming a 20mph speed differential, it will not affect the operational performance of median openings significantly and the delays caused by using substandard length left-turn lane are significantly less than the delays associated with the absence of dedicated left-turn lanes; 2) at the safety impacts perspective-substandard length left-turn lanes will affect the safety performance of median openings.
报告类型：	科技报告