Overview
The decision to install a left-turn accommodation is a complex one as state and local transportation agencies weigh the left-turn demand, the cost of the accommodation, and the anticipated operational and safety benefits. Clear and consistent application of left-turn accommodations is important for mitigating the impacts of left turns, both for reconstruction projects and for the permitting of new access points.
This report presents guidance for the selection and design of left-turn accommodations at unsignalized intersections. Eleven case studies of typical situations illustrate the use of the guidance. These examples are based on actual locations where left-turn treatments were considered, evaluated, and/or installed. Two of the examples involve analysis of a proposed development.
The contractor’s final report providing background information for the project is as NCHRP Web-Only Document 193. In addition to describing the work that was done, Appendix F presents a legal review of the impact of essential nexus and rough proportionality on development considerations.