West Coast EMT Block One Exam

At what speed does hydroplaning of an ambulance MOST likely occur on wet roads?

1. 30 mph

2. 10 mph

3. 20 mph

4. 15 mph

The correct answer is: 30 mph

Hydroplaning occurs when a vehicle's tires lose contact with the road surface due to a layer of water, causing a loss of traction. This phenomenon is more likely to happen at higher speeds, specifically when the vehicle is moving fast enough that the tires cannot push the water out of the way effectively. Research and guidelines suggest that hydroplaning can start to occur at speeds as low as 30 mph, especially on wet surfaces where water accumulation is significant. The engineering behind tire design also plays a role; tires are built to displace water but can only do so up to certain speeds. As such, identifying 30 mph as the most likely speed for hydroplaning aligns with statistical and practical observations in driving safety. Understanding this threshold is essential for EMTs and other emergency responders who must navigate wet roads safely.