Agency's final report documenting the entire research efforts is available online as NCHRP WOD 314: Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. It will be balloted by the AASHTO COBS in June 2022.
Of more than 600,000 bridges listed in the Federal Highway Administration's (FHWA) National Bridge Inventory, close to 1,000 are movable highway bridges. The design and installation of structural, mechanical and electrical systems provide significant challenges for designers, contractors and owners in any movable highway bridge project. The primary design specifications for movable bridge design and construction is the AASHTO LRFD Movable Highway Bridge Design Specifications published in 2000 with 2002 interim revisions. The second edition of the specifications was published in 2007, and the most recent interim revisions were in 2015. Based on the input from movable highway bridge owners, designers and industry representatives, there is an immediate need to incorporate reliability-based design methodology and to reflect advances in electrical, mechanical, and traffic/marine safety systems into the current specifications.
The objectives of this research were to (1) develop a reliability-based methodology to design electrical, mechanical, and traffic/marine safety elements and systems for movable highway bridges and (2) propose revisions to the AASHTO LRFD Movable Highway Bridge Design Specifications including all sections.