Develop, fabricate, and test surrogate bogey vehicles and pendulum masses with noses for evaluating MASH breakaway performance of luminaire poles, signs, and work zone devices
Roadside safety features are
utilized along U.S. highways and roadways to serve numerous purposes. For
example, longitudinal barriers are used to prevent errant vehicles from
striking rigid obstacles and steep slopes beyond the travel lanes. Signs
support systems provide messaging and travel guidance to motorists, while
luminaire pole systems provide lighting for night-time driving. Work-zone
traffic control devices are used to warn and alert motorists of an upcoming
construction zone as well as safely guide motorists through the
temporarily-effected roadway region.
Historically, roadside safety
features have been subjected to crashworthiness evaluations using a variety of
impact test specifications and/or guidelines. Some of guidelines have included:
AASHTO’s Standard and LRFD Specifications
for Structural Supports for Highway Signs, Luminaries, and Traffic Signals;
NCHRP Report No. 230; the AASHTO Guide
Specifications for Bridge Railings, and NCHRP Report No. 350. For these
evaluations of roadside safety hardware, both full-scale crash testing and
surrogate vehicle testing had been utilized. In recent years, AASHTO published
the Manual for Assessing Safety Hardware
(MASH) in 2009 and 2016. Within the MASH guidelines, surrogate vehicle testing
was no longer applicable due to a need to objectively assess critical system
behaviors resulting in damage and/or penetration of the passenger occupant
compartment, such as the windshield, roof, and floor pan. Surrogate vehicle
testing was historically used for evaluating many breakaway luminaire poles,
sign supports, and light-weight, work-zone traffic control devices (WZTCD) using
a representative low-mass, small car vehicle. Within the AASHTO MASH 2009 and
2016 guidelines, another vehicle test evaluation was required with a heavy
passenger vehicle, represented as a pickup truck.
With the AASHTO MASH guidelines,
elimination of surrogate vehicle testing, the addition of a pickup truck test
condition, the existence of numerous luminaire poles, sign supports, and work-zone
traffic control devices, and the increased cost to certify these devices,
crashworthiness evaluations and innovation have stagnated for many of these
devices. As a result, there exists a need to re-examine the use of surrogate
vehicle testing in the crashworthiness evaluations of luminaire poles, sign
supports, and light-weight, work-zone traffic control devices. The development
of robust, surrogate bogey vehicles, with an ability to largely capture vehicle
deformation and penetrations as well as accurate system behavior, would reduce
crash testing costs and promote greater innovation for new products for
manufacturers and state Departments of Transportation. Motorist safety of U.S.
roadways would be enhanced as more AASHTO MASH-compliant systems become
available and are implemented.
The main objective of the research study is to develop,
fabricate, test, and evaluate surrogate bogey vehicles and pendulum masses (referred
to a surrogate devices) for determining Test Level 3 MASH 2016 crashworthiness with
passenger vehicles for breakaway luminaire poles, sign supports, and work-zone
traffic control devices used in permanent and temporary applications. The surrogate
devices should be capable of providing cost-effective, compliant, impact
testing and evaluations of roadside safety hardware, while evaluating as many
critical behaviors and failure modes as deemed feasible and reasonable. From
this study, researchers will develop 3-D CAD details for the fabrication of
prototype, surrogate, MASH 2016 bogey vehicles, which pertain to the 1100C and
2270P passenger vehicles. The study will also result in 3-D CAD details for the
fabrication of a 1100C vehicle mass compatible with drop pendulums for use in
low-speed impact testing on a subset of breakaway features. Surrogate devices
will be fabricated and satisfactorily demonstrated under this study. Limited
validations will be performed. Recommendations will be provided regarding the
proper applications, test conditions, and limitations for the surrogate devices
as well as which critical behaviors and failure modes can be evaluated.
State DOTs are required to install crashworthy safety
hardware along freeways, interstates, highways, and roadways. In recent years,
AASHTO and FHWA agreed to a roadside safety hardware implementation plan corresponding
to AASHTO’s Manual for Assessing Safety Hardware (2016), which included breakaway
luminaire poles, sign supports, and work-zone traffic control devices. Each
hardware category consists of hundreds, maybe even thousands, of combinations
that require crashworthiness testing and evaluations. In addition, many of
these devices are provided by private industry and/or are proprietary. Further,
a greater number of tests are required under MASH 2016 for these hardware
categories, which increases overall crash testing costs using real vehicles.
Today, crash testing is required on a greater number of system combinations as
compared to many years ago. When considering these facts, a very limited number
of these devices have been tested and evaluated under the MASH 2016 impact
safety guidelines. Due to unavailability, our State DOTs have only implemented
limited quantities of MASH-compliant breakaway luminaire poles, sign supports,
and work-zone traffic control devices to date.
The development of surrogate testing devices would reduce
complaint testing costs, increase innovation, and promote testing and
evaluation of a greater number of devices in the noted roadside safety hardware
categories. Over time, more MASH-compliant devices would be placed along U.S.
highways and roadways, thus benefiting the motoring public and helping to
reduce roadside fatalities and serious injuries.
This research study would build upon historical bogey and pendulum
apparatuses that were developed and used for impact testing and evaluating
breakaway luminaire poles, sign supports, and lightweight WZTCDs across the
U.S. The noted test methods were used at the FHWA Federal Outdoor Impact
Laboratory (FOIL), Southwest Research Institute (SwRI), Texas A&M
Transportation Institute (TTI), Midwest Roadside Safety Facility (MwRSF),
Valmont-UNL Pendulum Testing Facility, E-Tech Testing Services Inc. (E-TECH),
and many other agencies. In recent years, the Florida Department of
Transportation, in collaboration with the University of Florida, developed and
used a crushable nose for a pendulum mass to evaluate the breakaway
characteristics of highway signs for MASH 1100C vehicles. Further, researchers
at George Washington University and the National Crash Analysis Center, now at
George Mason University and the Center for Collision Safety and Analysis
(CCSA), conducted research to develop a crushable nose for 1100C surrogate
A list of major tasks required to successfully complete the research study is provided below.
Phase 1 – Background, Brainstorming, and Preliminary Plan
- Task 1: Perform detailed literature review on development and use of surrogate testing (bogey vehicles and pendulum masses) for evaluating luminaire poles, sign supports, and work-zone traffic control devices. Also, review relevant automotive crash test results conducted by NHTSA and IHS.
- Task 2: Identify, discuss, and rank important features, properties, dimensions, and structural characteristics for the design of surrogate devices.
- Task 3: Identify, discuss, and rank critical system behaviors and failure modes that could be captured under impact testing with surrogate bogey vehicles and a pendulum mass.
- Task 4: Brainstorm multiple concepts for surrogate devices. Select preferred concepts and prepare preliminary sketches.
- Task 5: Prepare preliminary plan for developing and fabricating surrogate devices considering the ranked attributes from Task 2 and Task 3. Determine vehicle attributes and system behaviors that will be considered. Present findings via MS PowerPoint and virtual meeting. Obtain panel feedback and confirmation for the preliminary plan.
Phase 2 – Develop Surrogate Devices and Prepare Validation Testing Plan
- Task 6: Perform analysis and design to configure the surrogate devices.
- Task 7: As needed, utilize other methods (e.g., static testing, dynamic testing, finite element analysis, etc.) to supplement design process and consider critical attributes, features, and behaviors for surrogate devices.
- Task 8: Prepare 3-D CAD details with material specifications.
- Task 9: Prepare plan for conducting preliminary validation testing on surrogate devices.
- Task 10: Present findings, CAD details, and testing plan via MS PowerPoint and virtual meeting. Obtain panel feedback and confirmation for the fabrication and testing of surrogate devices.
Phase 3 – Fabricate Surrogate Devices and Conduct Validation Testing on Support Systems
- Task 11: Fabricate 1100C and 2270P surrogate devices (bogeys, pendulum mass, etc.).
- Task 12: Conduct vehicle handling testing and dynamic impact testing on support systems to validate surrogate devices. Repeat testing as needed. Document results from validation testing on support systems with surrogate devices.
- Task 13: Redesign and/or modify surrogate devices and update 3-D CAD details as needed.
- Task 14: Present findings and impact testing results via MS PowerPoint and virtual meeting. Obtain panel feedback and confirmation on final design of surrogate devices.
Phase 4 – Reporting, Dissemination, and Implementation
- Task 15: Prepare and submit draft and final research reports with final 3-D CAD details with material specifications along with summary, conclusions, recommendations and implementation guidance.
- Task 16: Disseminate research findings at national meetings to promote implementation of surrogate testing of breakaway luminaire poles, sign supports, and work-zone traffic control devices.
Research findings and results would be provided to state highway
agencies, accredited crash testing laboratories, roadside safety hardware
developers and manufacturers, as well as private industry. Design details and
material specifications for the MASH 2016 surrogate devices would be available
to the entire roadside safety community. Accredited testing laboratories as
well as private R&D divisions would fabricate the surrogate devices for use
in conducting compliant testing under MASH 2016 as well as low-cost R&D
testing with pendulums. State DOTs would implement the crashworthy hardware
resulting from the use of the new surrogate bogey vehicles and pendulum mass in
safety evaluations. This information would be disseminated in national forums
via PowerPoint presentations, research summaries, design manuals, and CAD plan
sets, including at Pooled Fund Safety Program meetings, Task Force 13 meetings,
AASHTO Technical Committee for Roadside Safety (TCRS) meetings, AASHTO T-12
meetings, and Transportation Research Board (TRB) AFB20 Committee on Roadside
Safety Design meetings.
The following list includes organizations that
would be interested in the research results and would support implementation:
AASHTO Committee T-12, Sam Fallaha, P.E., (850) 414-4296, firstname.lastname@example.org
AASHTO Committee T-7, Tim Keller, P.E., (614) 466-2463, email@example.com
TRB Committee AKB10, Richard Dunne, P.E., (609) 468-7051,
TRB Sub-Committee AKB10(1), Carl Macchietto, P.E., (402) 359-6735, firstname.lastname@example.org
AASHTO TCRS Committee, Keith Kota, P.E., (603) 271-1615, email@example.com
TRB Committee AFB20, Roger Bligh, Ph.D., P.E., (979) 317-2703, R-Bligh@tti.tamu.edu
Task Force 13, John Durkos,
(330) 346-0721, firstname.lastname@example.org
|Sponsoring Committee:||AKB10, Innovative Highway Structures and Appurtenances
|Research Period:||24 - 36 months|
|RNS Developer:||Richard Dunne, PE (AKB10 Chair), Ronald Faller, Ph.D., P.E., University of Nebraska-Lincoln,Carl Macchietto, P.E., Valmont Industries|
|Source Info:||Others Supporting the Problem Statement|
• AASHTO Committee T-12, Sam Fallaha, P.E., 850-414-4296, email@example.com
• AASHTO Committee T-7, Tim Keller, P.E., (614) 466-2463, firstname.lastname@example.org
• TRB Sub-Committee AFF10(1), Carl Macchietto, P.E., (402) 359-6735, email@example.com
Potential Panel Members
• Sam Fallaha, P.E., Florida DOT, AASHTO T-12, 850-414-4296, firstname.lastname@example.org
• Carl Macchietto, P.E., Valmont Industries Inc., (402) 359-6735, email@example.com
• Erik Emerson, P.E., Wisconsin DOT, AASHTO TCRS, 608-266-2842, Erik.Emerson@wi.gov
• Geoff Maus, P.E., TrafFix Devices Inc., 949-361-5663, firstname.lastname@example.org
• Bill Wilson, P.E., Wyoming DOT, 307-777-4216, email@example.com
• Dan Waddle, P.E., Nebraska DOT, 402-479-4594, firstname.lastname@example.org
• Ali Hangul, P.E., Tennessee DOT, 615-741-0840, email@example.com
• Doug Gabauer, Ph.D., Bucknell University, 570-577-2902, firstname.lastname@example.org
|Index Terms:||Crash tests, Breakaway supports, Poles (Supports), Sign supports, Traffic control devices, |
Safety and Human Factors
Bridges and other structures