Which deck type is most often present on moveable and rehabilitated bridges for reduced dead load and easier installation?

• A. Orthotropic decks
• B. Grid deck
• C. Steel decks
• D. Concrete decks

Answer: (B)

For moveable and rehabilitated bridges, the goal is to reduce dead load and simplify installation, so a lightweight, modular deck system is preferred. Grid decks use open steel grid panels that are significantly lighter than solid steel or concrete decks, which lowers the dead load the structure has to carry. They’re also easy to assemble in sections, often prefabricated, so installation is faster and damaged sections can be replaced without rebuilding the entire deck. The open grid design helps with drainage and maintenance access, which is especially helpful during rehabilitation. Orthotropic decks are technically light and efficient, but they require more complex fabrication and installation, making grid decks a more practical choice for quick rehabilitation and easier installation on moveable spans. Concrete decks are heavy and slower to install, while traditional steel decks don’t offer the same modular advantages as grid panels.