What is one advantage of using drainage troughs in bridge design?

Answer: B — They can divert excess water runoff

One significant advantage of using drainage troughs in bridge design is their ability to divert excess water runoff. Proper drainage is crucial in bridge construction as it helps prevent water accumulation, which can lead to structural damage, erosion, and unsafe conditions for vehicles and pedestrians. By channeling the water away effectively, drainage troughs minimize the risk of hydrostatic pressure and potential flooding under the bridge, thereby enhancing the longevity and safety of the structure. This proactive approach in design helps maintain the integrity of the bridge over time and reduces maintenance costs associated with water-related damage.