A Report on the Development of Guidelines for Applying Right-Turn Slip Lanes

This report serves as a summary of the research process regarding the application of right-turn slip lanes in the state of Texas. The work plan was divided into three phases: a review of available literature on the design and operation of right-turn slip lanes, focus group meetings to discuss the synthesis findings with Texas Department of Transportation (TxDOT) representatives, and production of design guidelines pertaining to right-turn slip lanes that accommodate mobility as well as pedestrian and bicyclist safety. The new construction guidance provided for urban and suburban roadways is inspired by the City of Ottawa’s “urban smart channel” design that incorporates a sharp angle of entry into the cross street (~70 degrees) and delineates a narrow turning path for passenger cars using pavement markings. This design promotes slower turn speeds and enhances visibility of the pedestrian crossing location. The sharp angle of entry reduces the head turning required of motorists to search for gaps in oncoming traffic and thus, improves driver comfort. The design includes a crosswalk located in the middle of the channelized roadway that is perpendicular to the turning roadway. The rural design guidance mainly centers on facilitating mobility through the slip lane, as regular pedestrian activity is not typical at rural intersections. Accordingly, the design promotes larger sweeping turns, the use of acceleration lanes, unpaved channelizing islands, and a flatter angle of entry into the cross street. The design guidelines also include a section on retrofitting treatments, targeting issues commonly found at right-turn slip lanes: absence of proper refuge for pedestrians, motorist noncompliance in yielding to crossing pedestrians, pedestrian noncompliance with the crosswalk location, high speeds in the channelized roadway, low visibility of crossing pedestrians, and excessive head turning to spot oncoming traffic.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Technical Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 144p

Subject/Index Terms

Filing Info

  • Accession Number: 01564437
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/TX-14/0-6810-1, 0-6810-1
  • Contract Numbers: 0-6810
  • Created Date: May 20 2015 10:24AM