Timber Deck is traditional for smaller bridges but maintenance challenges and susceptibility to decay.

• A. Timber Deck
• B. Precast Concrete Deck
• C. Orthotropic Steel Deck
• D. Undivided Carriageway

Answer: (A)

Timber decks are favored on smaller bridges because they are lightweight, straightforward to construct, and often cost-effective for short spans. This makes them a traditional choice where simplicity and local availability matter. However, timber is susceptible to moisture, rot, and insect attack, which means these decks require ongoing maintenance—regular inspections, protective treatments, and periodic replacement of worn boards or damaged members—to keep them safe and functional. That combination of being a common, traditional option for small structures and having clear maintenance and decay concerns is exactly what this description highlights.

Other deck types don’t fit as well. A precast concrete deck offers durability and lower maintenance in many cases, so it isn’t described as the traditional small-bridge option with decay susceptibility. An orthotropic steel deck provides strong performance for longer spans and involves corrosion protection considerations rather than timber decay, so it’s not the same maintenance narrative. An undivided carriageway refers to a traffic arrangement rather than a deck material, so it doesn’t address the material-specific maintenance and decay aspects described.