Determination of Zone of Intrusion Envelopes under MASH Impact Conditions for Barrier Attachments

Highway agencies often install safety countermeasures, such as pedestrian and bicycle railings, highway signage, high-protective screening fences, luminaire poles, etc., to the top or backside faces of crash-tested traffic barriers. These features may alter safety performance of the barrier systems. Thus, the Zone-of-Intrusion (ZOI) concept was developed to address this issue. ZOI represents the locations above and behind a barrier system that various vehicle components may occupy during an impact event. ZOI envelopes provide guidance for placement of roadside hardware appurtenances above or beyond the face of the barrier. Current ZOI guidance within the 4th Edition of the American Association of State Highway and Transportation Officials (AASHTO) Roadside Design Guide was developed based on National Cooperative Highway Research Program (NCHRP) Report 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features, TL-2, TL-3, and TL-4 testing. However, AASHTO and Federal Highway Administration (FHWA) recently agreed to implement the Second Edition of the Manual for Assessing Safety Hardware (MASH) crash testing standard, which utilizes different standardized vehicles, and may significantly change the barrier ZOI. Specifically, the Manual for Assessing Safety Hardware (MASH) pickup truck, utilized in TL-2 and TL-3 evaluations, has an increased weight and a higher center-of-gravity than the pickup truck used in NCHRP Report 350. Additionally, MASH increased the weight of the single unit truck by 25 percent and increased the impact speed for TL-4 impacts. The increases in weight and impact angle for MASH test 4-12 have also led to an increase in the minimum height to 36 in. for TL-4 barriers. It is expected that the ZOI envelopes for these vehicles may change under the Second Edition, MASH criteria. Also, differences in barrier shape and height may affect the shape of ZOI envelopes. Therefore, a need exists to develop ZOI guidance for MASH barriers. The objective of this research is to: (1) develop ZOI envelopes for a variety of rigid barriers under MASH criteria; and (2) develop guidance for state transportation agency practitioners along with documentation intended for inclusion in the AASHTO Roadside Design Guide. The NCHRP is seeking the insights of proposers on how best to achieve the research objective. Proposers are expected to describe research plans that can realistically be accomplished within the constraints of available funds and contract time. Proposals must present the proposers' current thinking in sufficient detail to demonstrate their understanding of the issues and the soundness of their approach to meeting the research objective.  The research plan should: (1) include a kick-off teleconference with the research team and NCHRP convened within 1 month of the contract’s execution; (2) address the manner in which the proposer intends to satisfy the project objective; (3) be divided logically into detailed tasks that are necessary to fulfill the research objective and include appropriate milestones and interim deliverables; (4) incorporate opportunities for the project panel to review, comment, and approve milestone deliverables including one face-to-face meeting with the panel; (5) coordination with AASHTO Technical Committee on Roadside Safety (TCRS) via NCHRP-hosted WebEx teleconference to provide opportunities for feedback. TRB will cover the costs associated meetings at TRB facilities, teleconference services, and any approved panel travel. Consider at a minimum inclusion of the following for MASH TL-2, TL-3, and TL-4: 1. Identify the barrier height thresholds for each test level;   2. For these thresholds, determine the relationship between barrier heights and ZOI; 3. Evaluate rigid barrier shapes including: (a) New Jersey Shape; (b) F-Shape; (c) Single Slope; (d) Vertical shaped barriers; and (e) low profile barriers; and 4. Validate the data (e.g., based on in-service performance, crash tests etc.). Deliverables should include at a minimum: 1. Documentation intended for inclusion in the AASHTO Roadside Design Guide; 2. Prioritized recommendations for similar future research; 3. A final report documenting the entire research effort including methodology for determining and reporting the ZOI; 4. An executive summary of the project; 5. A PowerPoint-style presentation describing the background, objectives, research approach, findings, and conclusions; 6. A stand-alone technical memorandum titled “Implementation of Research Findings and Products” (see Special Note D for additional information); and 7. Recommendations for practitioner outreach, education, and assimilation into existing manuals. The contractor is expected to make presentations at no more than two AASHTO/committee meetings and incorporate related travel expenses in the budget. Proposers may recommend additional deliverables to support the project objective.

Language

  • English

Project

  • Status: Proposed
  • Funding: $400000
  • Contract Numbers:

    Project 22-34

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Crichton-Sumners, C

  • Start Date: 20171120
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 41647

Subject/Index Terms

Filing Info

  • Accession Number: 01634976
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 22-34
  • Files: TRB, RiP
  • Created Date: May 19 2017 1:00AM