Development and Evaluation of Crashworthy Approach Guardrail Transition with Increased Span Length between Concrete Bridge Rail and First Transition Post: Phase I

The Midwest Roadside Safety Facility (MwRSF) has recently conducted multiple research projects to develop crashworthy retrofits or design alterations for Approach Guardrail Transitions (AGTs) when the site conditions prevent the as-tested design configuration from being implemented. These research projects have mainly focused on issues that obstruct AGT posts from being properly installed (i.e., wing walls, drainage structures, utilities, and reduced grading). Most of these obstructions are located near the bridge railing end at the AGT's downstream region, where the posts are spaced closely together. Designing a new MASH crashworthy AGT that incorporates a large span length between the bridge rail end and the first transition post would avoid these obstructions and prevent the need for design retrofits. In 2020, a MASH TL-3 crashworthy AGT was created by the MwRSF for a steel-tube bridge rail for the Illinois and Ohio DOTs. This AGT had a 9-ft span length between the first bridge rail post and the adjacent transition post, which was designed to extend over ground obstructions near the bridge end. This AGT design used two HSS6x6x1/4 transition rail elements to match the specific steel-tube bridge rail configuration. However, a similar AGT could be developed using strong rail elements to prevent large deflections.

Language

• English

Project

• Status: Active
• Funding: $175,145.00
• Sponsor Organizations:

  Nebraska Department of Transportation

  1500 Nebraska 2
  Lincoln, NE  United States  68502
• Project Managers:

  Halsey, Lieska

• Principal Investigators:

  Yosef, Tewodros

  Faller, Ronald

  Fang, Chen

  Bielenberg, Robert

  Rosenbaugh, Scott

• Start Date: 20230701
• Expected Completion Date: 20250531
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Evaluation and assessment; Guardrail transition sections
• Identifier Terms: AASHTO Guide Specifications for Bridge Railings; Nebraska Department of Transportation
• Subject Areas: Design; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 01881383
• Record Type: Research project
• Source Agency: Nebraska Department of Transportation
• Files: RIP, STATEDOT
• Created Date: Apr 27 2023 2:46PM