Design Standards for Unobstructed Sight Lines at Left-Turn LanesStatus: CompleteReport Date: 09/09/2019 Summary: Positive offset left-turn lanes are one solution to improving left-turning motorists visibility of opposing through and right-turning traffic. MnDOT is revising its Road Design Manual and seeks to incorporate more information, policies and design guidance regarding positive offset left-turn lanes. Researchers from the University of Wisconsin's Traffic Operations and Safety Laboratory reviewed safety performance data from research that examined left-turn offsets. They also consulted 23 state DOT road design guides to understand the extent of available guidance. Findings from this research effort were used to develop extensive revisions to the Road Design Manual, addressing a wide range of design factors and applications of the positive offset left-turn lane throughout Minnesota's highway system. Final Deliverables: Design Standards for Unobstructed Sight Lines at Left-turn Lanes (Report #2019-32) Design Standards for Unobstructed Sight Lines at Left-Turn Lanes (Research Summary) Related Materials: Design Standards for Unobstructed Sight Lines at Left-Turn Lanes (Blog Post) Related Research: Examining Optimal Sight Distances at Rural Intersections Project Personnel: Principal Investigator: David Noyce Co-Principal Investigator: Madhav Chitturi, Andrea Bill Technical Liaison: Kristi Sebastian Project Coordinator: David Glyer Panel Members: Douglas Carter - Project Management and Technical Support James Rosenow - Project Management and Technical Support Joe Gustafson - Washington County Public Works - Engineer Jon Krieg - Kaare Festvog - Metro District Ken Levin - Hennepin County Lars Impola - Metro District Mark Vizecky - State Aid for Local Transp Mitchell Bartelt - Metro District Tiffany Kautz - Traffic Engineering Tim Plath - City of Eagan - Engineer