Institute for Transportation

About the research

The Iowa Department of Transportation (DOT) has received funding for an Accelerated Innovation Deployment (AID) project from the Federal Highway Administration (FHWA) to construct bridges using box beams made with ultra-high-performance concrete. Through the use of this approach to accelerated bridge construction (ABC), the duration of off-site detours during the course of a project will be reduced. The reduced construction timeline is expected to translate into improved safety for the traveling public, as the shortened duration of off-site detour routes would reduce exposure and the potential for crashes to occur along those routes.

The proposal submitted to the FHWA by the Iowa DOT called for the following with respect to safety:

• Improved safety as a product of the goal [of employing ABC].
• The performance goal of achieving a work zone crash rate equal to or less than the existing conditions.
• Work zone safety will be improved through the use of prefabricated bridge components. The ABC methods reduce the duration of the off-site traffic detour.

These goals point toward the need to establish what the impacts to safety are during construction of the new bridges, as well as how that compares to safety for comparable projects using traditional bridge construction.