ESTIMATING THE IMPACTS OF ACCESS MANAGEMENT TECHNIQUES: FINAL RESULTS

This research report summarizes the research activities and findings of the 2.5-year research project to investigate the impacts of access management treatments. The first objective of the project was to estimate the impacts of access management techniques through field data collection at selected sites in Texas and to perform simulation of traffic performance. Findings related to travel time and delay from three case studies are provided in this report. Theoretical corridors were also created and analyzed to provide further insight into corridor performance with changes in median type, driveway density, and traffic volume. The researchers identify key considerations for using microsimulation (VISSIM) for investigating access management treatments. Generally, the research identified a range of differences in travel time (and relatively small changes in speed) when comparing a corridor with a two-way left-turn lane (TWLTL) with the installation of a raised median along the three case study corridors and three theoretical corridors. The reduction in the number of conflict points along the corridors with access management was large (up to 60% for the case studies and up to 75% for the theoretical corridors). The reduction in conflict points illustrates the potential safety impacts of access management. The second objective of the research was to estimate the safety benefits of access management treatments by investigating crash data from select corridors where access management treatments have been installed. A key part of this analysis is the assessment of the crash information used in the analysis. The research identified a relationship between increasing access point density and increasing crash rates. It also identified a reduction in crashes when comparing corridors with a TWLTL with those with a raised median. Crash severity was also reduced with the raised median.

• Supplemental Notes:
  • Project Title: Benefits of Access Management. Report date: May 2004; Resubmitted: October 2004.
• Corporate Authors:

  Texas Transportation Institute

  Texas A&M University System, Information Technology Exchange Center
  College Station, TX  United States  77843

  Texas Department of Transportation

  Research and Technology Implementation Office, P.O. Box 5080
  Austin, TX  United States  78763-5080

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Eisele, W L
  • Frawley, W E
  • Toycen, C M
• Publication Date: 2004-10

Language

• English

Media Info

• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 264 p.

Subject/Index Terms

• TRT Terms: Access control (Transportation); Case studies; Crash data; Crash rates; Crash severity; Data collection; Field studies; Impacts; Microsimulation; Traffic conflicts; Traffic delays; Traffic safety; Traffic simulation; Travel time; Two way left turn lanes
• Identifier Terms: VISSIM (Computer model)
• Uncontrolled Terms: Access point density; Raised medians
• Geographic Terms: Texas
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 00987638
• Record Type: Publication
• Report/Paper Numbers: FHWA/TX-04/0-4221-2,, Technical Report 0-4221-2
• Contract Numbers: Project No. 0-4221
• Files: TRIS, USDOT, STATEDOT
• Created Date: Mar 7 2005 12:00AM