Development and Evaluation of Approach Guardrail Transition with Increased Span Length between Concrete bridge Rail and First Transition Post - Phase II

Phase I of this project, funded by the Nebraska Department of Transportation (NDOT), addressed this need at the concept and simulation level. Midwest Roadside Safety Facility (MwRSF) researchers developed and refined several long-span approach guardrail transition (AGT) concepts for the 34-inch tall NDOT thrie-beam system and used LS-DYNA simulations to evaluate their performance with increased span between the concrete buttress and the first transition post under MASH TL-3 impact conditions. The work included evaluation of the upstream W-beam to thrie-beam transition, the downstream thrie-beam to rigid buttress connection, and identification of critical impact points for both the pickup truck and small car tests. These analyses demonstrated that the selected long-span concept is a promising candidate, but they do not satisfy Federal Highway Administration (FHWA) requirements. Federal acceptance of new roadside safety hardware under the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) requires full-scale crash testing. An FHWA eligibility letter cannot be obtained on the basis of simulations alone. Without full-scale crash testing, the long-span AGT system cannot be fully validated, adopted statewide, or included in NDOT standard plans. Phase II is therefore needed to conduct the required full-scale MASH TL-3 crash tests and provide an FHWA-compliant evaluation of the new long-span AGT system.

Language

• English

Project

• Status: Programmed
• Sponsor Organizations:

  Nebraska Department of Transportation

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

  Halsey, Lieska

• Principal Investigators:

  Yosef, Tewodros

  Alomari, Qusai

  Faller, Ronald

  Rosenbaugh, Scott

  Bielenberg, Robert

• Start Date: 20260701
• Expected Completion Date: 20280531
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Bridge railings; Guardrails; Long span bridges; Simulation
• Identifier Terms: LS-DYNA (Computer program); Nebraska Department of Transportation
• Geographic Terms: Nebraska
• Subject Areas: Bridges and other structures; Design; Highways;

Filing Info

• Accession Number: 01991711
• Record Type: Research project
• Source Agency: Nebraska Department of Transportation
• Files: RIP, STATEDOT
• Created Date: Jun 2 2026 12:25PM