U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
Robert Sperry, P. E.
by Robert Sperry, P. E. on April 26, 2011
Local Roads Safety Liaison
Iowa LTAP, Center for Transportation Research and Education (CTRE)
I would like begin by thanking FHWA Deputy Administrator Greg Nadeau for the opportunity to respond to the article in this edition of the EDC Forum on "Why Use the Safety EdgeSM". This forum provides an excellent sounding board for all of us to share experiences on the innovative work that is being undertaken, thereby speeding up the 'learning curve' for others. In my opinion and based on the experiences our team had this past year, the biggest barrier to the implementation of the Safety EdgeSM is "fear of the unknown", (ie. The lack of knowledge about the Safety EdgeSM and how to properly use it), by agency inspectors, engineers and contractors. The benefits of implementing the Safety EdgeSM are many and I believe they will be even further proven as more projects incorporate this mitigation strategy.
Adoption of the Safety EdgeSM by the Iowa DOT was mandated for all state projects in January 2010 by then Chief Engineer Kevin Mahoney, really giving a jump start to our state's interest and activity. Then the Center for Transportation Research and Education (CTRE) team at Iowa State University was given the great opportunity this past summer to carry out a project sponsored by the FHWA Iowa Division regarding the Safety EdgeSM. This project involved developing educational materials, marketing to counties and conducting some analysis of the Safety EdgeSM.
Through the use of these tools and assistance provided to the local agencies, we were able to promote, track and evaluate many projects and better understand what was working best in Iowa. We also conducted three open houses around the state to broaden the knowledge base of area engineers and contractors. Although the ease of mounting and using the Safety EdgeSM device made the concept easy for agencies to adopt, other issues with base width/alignment, rollover, and slope consistency in Safety EdgeSM became apparent and had to be addressed.
Fortunately, most of the contractors and inspectors were receptive to new ideas on adjusting procedures slightly to preserve the edge slope that the paver produced. Some contractors had gained enough confidence and knowledge about the desired result (30 degree Safety EdgeSM slope) that two of the Hot Mix Asphalt contractors actually fabricated their own shoe designs, hoping to minimize any needed changes to their "normal" rolling procedures. Both designs worked with varying degrees of improvement, so I feel sure that more improvement modifications will be made by vendors (and contractors) in the upcoming year as well. PCC paving contractors on both of the county projects that our team followed were enthused by the challenge to make this new mitigation strategy work successfully. Both easily provided consistent slope shape and angle for the Safety EdgeSM they produced using the pan modifications which they designed and fabricated.
Several of the contractors' and inspection personnel recognized the goal of the Safety EdgeSM, but seriously doubted that it could really be of any significant value. However, "field tests" of the Safety EdgeSM (before final shoulder material was applied) usually changed their minds.
"I myself was a little skeptical about how well this would work and would it really make a difference; well I believe after testing it by running on and off the edge at different speeds and finding the ease of coming back on without being thrown into the other lane of traffic, I am a believer."
Educational opportunities and experiences with the Safety EdgeSM in Iowa this year have solidified our joint efforts to find ways install it even more effectively and we are now fortunate to have a multi-industry team working together toward that goal.
Thanks for the information and support in promoting the Safety EdgeSM implementation in Iowa and let's all keep spreading the message!