MOVABLE CONCRETE MEDIAN BARRIER: RISK ANALYSIS OF DEFLECTION INTO OPPOSING TRAFFIC

A movable concrete safety-shape barrier has been proposed for use in a reversible lane configuration on the Tappan Zee Bridge of the New York State Thruway. Previous tests indicate that this barrier provides performance comparable to standard rigid-concrete safety shape barrier, except for deflecting laterally on impact. Because of the narrow median width on this structure, concern arose that an impact on this barrier might cause it to deflect into opposing traffic, causing interference with another vehicle. This report concerns a model developed to assess the risk of interference collisions. Traffic and geometric conditions on the structure and the barrier's deflection characteristics were used to calculate the probability that a primary impact on the barrier would result in interference with opposing traffic. The model was programmed on a microcomputer spreadsheet to facilitate examination of various input parameters. For the conditions examined, risk of interference impacts with opposing traffic is low, even though the barrier deflects into the adjacent lane for some impacts. This low risk can be compared to the benefits anticipated from use of the movable barrier, to determine whether its introduction is justified.

• Corporate Authors:

  New York State Department of Transportation

  Engineering Research and Development Bureau, 1220 Washington Avenue
  Albany, NY  United States  12232

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Bryden, J E
  • Bruno, N J
• Publication Date: 1988-12

Media Info

• Features: Figures; References; Tables;
• Pagination: 30 p.

Subject/Index Terms

• TRT Terms: Bridges; Interference; Median barriers; Opposing traffic; Performance; Portable equipment; Reversible traffic lanes; Risk analysis; Shape
• Uncontrolled Terms: Configuration
• Old TRIS Terms: Concrete safety shapes; Lateral movement
• Subject Areas: Bridges and other structures; Design; Highways; Safety and Human Factors; I85: Safety Devices used in Transport Infrastructure;

Filing Info

• Accession Number: 00479284
• Record Type: Publication
• Report/Paper Numbers: FHWA/NY/RR-88/145, Res Rept 145
• Files: TRIS, ATRI, USDOT, STATEDOT
• Created Date: Jan 31 1989 12:00AM