Citation

Nemeth ZA. Transp. Res. Rec. 1978; 681: 62-69.

Copyright

(Copyright © 1978, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The results of a research project to synthesize existing information on continuous two-way left-turn median lanes and to conduct before-and-after studies to evaluate the effectiveness of such lanes as an access control measure are presented. Recommendations were prepared for the traffic engineer concerned with the evaluation of a situation in which a two-way left-turn median lane is a potential solution to existing capacity and safety problems. The research approach included studies in three distinct areas: a nationwide expert opinion survey, a literature review, and before-and-after field studies. Both the literature review and the survey indicated that two-way left-turn median lanes work well in spite of a wide variety of methods of signing and marking. There is uniform agreement that these lanes have excellent safety records; specifically, head-on collisions in the lanes are extremely rare. The before-and-after studies demonstrated that the effectiveness of the lanes and public reaction depend on proper engineering. A step-by-step decision-making strategy has been developed for the implementation of two-way left-turn median lanes.