United States Department of Transportation
i
Design Standards for Unobstructed Sight Lines at Left-turn Lanes
-
2019-08-01
-
[PDF-5.79 MB]
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Edition:Final Report
-
Corporate Publisher:
-
Abstract:Past research has clearly shown that obstructed sight lines at intersections lead to greater possibilities of collisions between left-turning vehicles and opposing oncoming vehicles. Evaluations of the effects of left-turn lane offsets, reported that positive left-turn lane offsets were more effective in reducing intersection left-turn crashes than zero and negative left-turn offsets. Several researchers have developed guidelines for geometric design elements of left-turn offset. The majority of states provide only a limited discussion on this topic. Florida DOT provides the most comprehensive policies and guidance for assuring unobstructed sight lines at left-turn lanes. Recommendations developed in this project center on general policies and guidance for designing offset left-turn lanes for a new edition of MnDOT’s Road Design Manual. Recommendations are organized to provide standards, policies, and guidance for new/reconstruction projects and for preservation projects. Topics covered include definition of left-turn lane offset, design factors impacting offset, suggested designs for urban and rural multilane roadways and expressways, accommodating U-turns, pedestrian and bicyclist considerations as well as winter maintenance considerations. Additional recommendations are offered to improve consistency among all MnDOT manuals and guides used for intersection design and operation.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
