Clear Zone: A Synthesis of Practice and Benefits of Meeting the Ten-Foot Clear Zone Goal on Urban Streets

All design engineers understand that providing a clear zone of ten feet or more is good practice in most, but not all, situations. Exceptions to the ten feet goal might include traffic calming treatments and context sensitive solutions. However, more guidance is needed to understand when it is practical and cost effective to provide something less than ten feet. Further, urban roadway design engineers and municipal engineers need some assurance when they consider all engineering criteria, and it is still not practical to provide ten feet of clear zone space so their project will be positively reviewed by the Iowa DOT. The objectives of this research are threefold: 1) determine the state of the practice of clear zone design guidance (standards) and the experiences other jurisdictions have had with applied clear zone guidance, 2) identify experience in other jurisdictions with clear zone guidance with respect to application of traffic calming designs and/or context sensitive solutions, and 3) observe the benefits or dis-benefits in Iowa that have resulted from providing ten feet of clear zone or from providing less than the ten foot goal.


    • English


    • Status: Active
    • Sponsor Organizations:

      Iowa Highway Research Board

      Iowa Department of Transportation
      800 Lincoln Way
      Ames, IA  United States  50010
    • Performing Organizations:

      Midwest Transportation Consortium

      Iowa State University
      Ames, IA  United States  50010-8664
    • Principal Investigators:

      Maze, Tom

    • Start Date: 20060601
    • Expected Completion Date: 0
    • Actual Completion Date: 0
    • Source Data: RiP Project 12104

    Subject/Index Terms

    Filing Info

    • Accession Number: 01460530
    • Record Type: Research project
    • Source Agency: Midwest Transportation Consortium
    • Files: UTC, RiP
    • Created Date: Jan 3 2013 1:26PM