Development of Guidance for Non-Standard Roadside Hardware Installations
safety hardware such as guardrail is crash tested to assess the crashworthiness
of the device. The current crash test criteria is contained in the AASHTO Manual
for Assessing Safety Hardware (MASH) and all highway agencies are in the
process of implementing MASH hardware on their systems. Like all hardware
assessment however, MASH testing is conducted within the sterile, idealized
environment of a laboratory test deck.
In practice, conditions are seldom so ideal.
frequently encounter situations where the approved roadside safety hardware
will not fit the location. Agencies may address these situations with special
site-specific designs. Some possible examples of non-standard roadside
applications could be:
• Modifying a crash
tested barrier to fit a location (e.g. Install posts with less embedment than
what was tested).
• Using a radius
guardrail at an intersection where there is not enough room for a crash tested
• Using an older
crash test standard (e.g. a MASH approved approach transition may not fit at a
location so an NCHRP-350 transition is used).
• Determination to
not provide shielding (e.g. delineate an object).
• Only shield some obstacles
at a location (e.g. shield blunt edge of bridge, some of the steep slope but
not all the steep slope).
This research will
develop guidance for “non-standard roadside applications” where standard
practices of crash tested barrier cannot be used.
This research will develop guidance for “non-standard roadside applications” where standard practices of crash tested barrier cannot be used.
Roadside safety hardware is critical
for reducing severe crashes on the nation’s highways. While approved crash tested hardware reduces
the risk of severe crashes for the majority of applications, situations may be
encountered where the approved roadside safety hardware does not fit the specific
location. There is an urgent need to
develop guidance for special site-specific designs to guide the highway
Agencies on appropriate hardware use. Absence
of standard hardware application is not an excuse to do nothing; some reasonably
safe solution is better than nothing at all.
In the absence of this research, the frequency of severe injury and fatal crashes will likely escalate as more miles of roadway with no, or non-standards roadside hardware installations continue to increase.
research is related to approve crash tested systems for existing (or past)
roadside safety hardware testing and evaluation standards. Although highway Agencies often encounter
situations where approved roadside safety hardware does not fit the existing
location, there is no specific documentation of practices designed to mitigate
these problems. Neither are guidelines
available on how the Agencies should address these situations. Irrespective of this perceived lack of
resources, a literature search should be conducted to identify to the extent
possible, non-standard practices in the field.
The objective of this research is to:
non-standard situations that are encountered by highway Agencies
Investigate potential crash tested solutions for these situations,
Identify best practices for
situations where a crash tested solution may not be practical
Develop a general
methodology that Agencies can apply to any non-standard situations
Decrease to the extent
possible, the tort liability placed on Agencies when they apply non-standard
The result of this research project
will provide a guidance to assist state, local and tribal agencies to provide
the most practical solution for non-standard roadside hardware installation
conditions. The guidance could be
further implemented through an update of appropriate sections of the AASHTO
Roadside Design Guide (RDG). Recommended
guidance or specific solutions could be incorporated into a future update of MASH with proper review and consideration
by AASHTO Technical Committee on Roadside Safety (TCRS).
Results of this research and the
resulting guidance will be disseminated to state DOT design engineers,
consultants, and practitioners through presentations and webinars at
appropriate industry and professional meetings including TRB Roadside Safety
Design Committee, AASHTO TCRS, and Committee on Bridges and Structures
Technical Committee T-7 “Guardrails and Bridge Rails.”
Results of this research and the resulting guidance will be disseminated to state DOT design engineers, consultants, and practitioners through presentations and webinars at appropriate industry and professional meetings including TRB Roadside Safety Design Committee, AASHTO TCRS, and Committee on Bridges and Structures Technical Committee T-7 “Guardrails and Bridge Rails.”
|Sponsoring Committee:||AFB20, Roadside Safety Design
|Research Period:||24 - 36 months|
|RNS Developer:||Alex Price, Erik Emerson, Chiara Silvestri Dobrovolny, Joseph Jones, and Roger Bligh|
|Source Info:||TRB AFB20 Mid-Year Meeting 2019, Reno NV|
|Index Terms:|| |
Safety and Human Factors