The managed lane concept is currently being considered on major freeway projects in Texas cities. As a new concept in operating freeways it has a limited experience base, creating a knowledge vacuum in emerging key areas that are critical for effective implementation. Complicating the effort is the rapid progress of several freeway improvement projects in Texas for which managed lane operations are proposed. The operational experience both in Texas and nationally for managed lanes is minimal, particularly for extensive freeway reconstruction projects. The managed lane projects currently in existence involve retrofits of existing freeway sections within highly fixed access, geometric, operational configurations and established eligibility considerations. There are virtually no projects in operation from which to draw experiential data on the implementation of managed lane freeway sections with multiple operational strategies, including variations in eligible vehicle user groups by time of day. Tools are available that document the impact of managed lane operations on the road users who make up the vehicle mix. Traffic simulation is a tool that affords the possibility of examining the operational impacts of a vast array of design alternatives for managed lanes; in the current research, the VISSIM simulation tool was used. Whereas such models are historically used to evaluate freeway and arterial design alternatives, with the user selecting the designs which produce the most significant benefits, the models themselves are flexible enough to test scenarios and provide performance data throughout the design and development process. This effort analyzes a variety of managed lane access and egress scenarios and makes weaving length recommendations for managed lanes access. The report provides maximum desirable weaving volume values, and gives additional guidance to assist engineers and planners in the determination of freeway ramp and managed lane access spacing.


  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 62 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00939841
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/TX-02/4160-4,, Research Report 4160-4,, TTI: 0-4160
  • Contract Numbers: Project No. 0-4160
  • Created Date: Mar 27 2003 12:00AM