What is the name of the document published by AASHO in 1927 as the first national design specification for highway bridges?

• A. Bridge Construction Guidelines
• B. National Highway Design Code
• C. Structural Design Manual
• D. Bridge Design Specifications

Answer: (D)

This question tests knowledge of the historic origin of the first nationwide standard for highway-bridge design. In 1927, the American Association of State Highway Officials (AASHO) published Bridge Design Specifications, the first national code that set uniform criteria for bridge design across states. Before this, states followed varied practices, which could lead to inconsistent safety and performance. The Bridge Design Specifications provided standardized rules for loads, analysis, materials, and detailing, enabling engineers to design bridges to a common performance level. The other listed titles don’t correspond to the historic 1927 publication, making Bridge Design Specifications the correct name. This publication laid the groundwork for the later national codes used today.