While people tend to evaluate how necessary a trip is before driving in snowy weather, few have any qualms about driving in the rain. You'll want to go a little slower due to poorer visibility, but you generally don't have to worry about dangerous conditions.

When a gentle rainfall turns to a downpour, though, you'll want to be more cautious. Flooding can quickly occur when the rain comes down faster than the ground and runoff channels can absorb it.

Drivers often underestimate the depth or power of floodwaters on a road, or overestimate the ability of their vehicle to navigate this hazard. The National Oceanographic and Atmospheric Administration says more than half of all flood-related deaths occur when people drive into the water, with many drowning as their vehicle is swept away.

It does not take much water to make a vehicle inoperable. Many vehicles have only six inches of clearance from the ground, and one foot of water can carry away a small, low-slung car. Most vehicles can be picked up and carried off when the water's depth reaches two feet.

Even if the water on the road looks shallow enough to drive through, it might hide submerged hazards. Potholes or debris under the water can damage or disable your vehicle. Severe floods can wash away the road and its underlying surface, creating a deeper depression than you might expect.

If it looks like it will be unsafe to navigate an unsafe section of road, turn around and find another way to your destination. Water is often too deep to traverse when it appears in areas with dips or depressions in the elevation, and vehicles can easily be swept away when the water crests the roadway on a bridge. Never drive around any barricades or warning signs that have been set up on the road.

Floodwaters can damage your vehicle in a number of ways. If enough water is ingested through your air intake while driving through the water, it will cause your engine to stall. When you drive fast enough, water can be sucked into the engine. In addition to having to rescue your vehicle from the water, you'll be stuck with an expensive repair bill since the engine will need to be partially disassembled to expel the water.

Even if your vehicle's air intake is located at a higher height, water can seep into the cabin and damage the carpets and other fabrics. Bob Collins, writing for Minnesota Public Radio, says water can also get into your oil pan if you drive through standing water.

Other damage can result when chilly water comes into contact with hot vehicle components. This temperature change can causes rapid contraction and can crack or warp parts such as the catalytic converter and brake rotors.

When it is possible to traverse a flooded road, you'll want to do so carefully. The Automobile Association, an English organization, says hydroplaning is more likely at high speeds. This condition occurs when the tires are not able to dispel enough water through their treads, thus making it harder to steer and increasing your stopping distance.

In addition to increasing the possibility of engine damage, driving into standing water at a high speed can throw up large waves on either side of the vehicle. This water can come down on oncoming vehicles, impeding the vision of other drivers. It can also soak pedestrians on the side of the road.

Slow down when driving through shallower floodwaters. Proceeding in this way will protect your engine and allow you to keep control. Switching to a lower gear while you ford these waters can also help prevent engine damage.