At speeds over what limit can hydroplaning occur in a standard passenger car?

Answer: B — 30 mph

Hydroplaning is a phenomenon that occurs when a vehicle's tires lose contact with the road surface due to the presence of water, causing the vehicle to slide on the water layer. At speeds around 30 mph, the risk of hydroplaning significantly increases, as this is the typical threshold where tires may not be able to effectively displace water on the road. At this speed, water can build up in front of the tires faster than the tires can push it away, leading to reduced traction and control. This is particularly true when there is standing water on the roadway. Therefore, understanding that hydroplaning becomes a notable concern at this speed is vital for safe driving practices, especially in wet conditions. Keeping vehicle speed lower than this threshold can help maintain tire contact with the road surface and enhance safety.