The AASHTO LRFD Guide Specifications for the Design of Movable Highway Bridges, Third Edition (2023), provide design provisions for highway movable bridges covering structural, seismic, vessel collision, mechanical, hydraulic, and electrical design. The specifications apply to bascule, swing, and vertical lift bridge types. General provisions define component classifications and special requirements for contractor-supplied information and equipment. Sections on structural design cover movable bridge design features and requirements, while seismic sections address seismic loads, limit states, and response modification factors. Mechanical sections treat design loads and power requirements and bridge-type-specific machinery design, complemented by hydraulic and electrical design sections. The specifications also establish requirements for movable bridge operation and control. They are intended for engineers designing and specifying movable highway bridges for highway agencies.