Flood plain criterion purpose for access roads?

• A. To ensure roads remain usable during flood events.
• B. To increase travel speed.
• C. To reduce construction cost.
• D. To allow construction near rivers.

Answer: (A)

The main idea is to keep roads usable when floods occur. A flood plain criterion for access roads focuses on reliability and connectivity during high water, not on speed or cost. Engineers study how high water rises and how fast it flows in the area and design the road so it won’t be overtopped or washed out during typical flood events. This often means elevating the road, selecting routes less prone to flooding, and providing adequate drainage and bridges that can handle floodwater and debris, with a safety margin called freeboard. The goal is to preserve access for evacuation, emergency response, and continued movement of people and goods even when surrounding areas are flooded.