Right and Left Turn Lane Warrants

The genesis of this project stems from a perception by city and county engineers that there is a lack of guidance relative to the installation of right and left turn lanes along local road systems. An initial review found the Minnesota Department of Transportation (MnDOT) Road Design Manual (RDM) has guidance for when turn lane installation is warranted along the State’s roadway system, but the focus is reconstruction. Many times separated turning and through volumes are required in order to determine whether or not a turn lane is needed, as well as to determine the length of the turn lane. This lack of guidance for local systems may cause some agencies to miss out on opportunities to build turn lanes when needed, to work with the zoning (permitting) authority and/or to have a developer pay for the cost of a turn lane as part of their development project. CH2M HILL was asked to conduct a literature review to determine what existing turn lane guidance is available and being used by different agencies. The review focused on six key areas that local agencies are concerned with and encounter when deploying turn lanes on their road systems and include both long-term and short-term scenarios. Consistent with MnDOT Transportation Research Syntheses, the objective of this project is to search existing literature and how it relates to the topic of providing guidance for installing right and left turn lanes along local systems, but not about developing new guidance. The summary of those findings are in this report, along with suggested next steps, followed by the individual literature results.


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Filing Info

  • Accession Number: 01600672
  • Record Type: Publication
  • Created Date: May 25 2016 12:31PM