Drive Safe in a Flood

Whether it is a severe thunderstorm, hurricane or other tropical weather system, heavy rainfall anywhere in the United States causes flooding problems.

When a large amount of rain falls over a short period of time, ditches, rivers and lakes become filled with water and overflow into low-lying or poorly drained areas. In addition to the high frequency of excessive rainfall events, the impacts of flooding may increase as population and urban development grows.

Flood Statistics
Statistics clearly point out the high risk of driving in and around flooded roads and low spots. Usually, individuals between the ages of 30-39 years old attempt to drive through flooded roads only to be wisked away by rushing waters. The rule is simple: If you cannot see the road or its line markings, do not drive through the water.

Effect of Moving Water on Vehicles
Moving water exerts a pressure on an object such as a car or person. As water depth increases or a greater area is exposed to moving water, a greater force will be exerted. Also, as a surface becomes slippery, friction is reduced. Water, sand, or mud tends to replace the frictional forces that hold a car in place.

Consideration of Sport Utility Vehicles (SUVs)
Even though the weight of Sport Utility Vehicles (SUVs) may appear to offer a greater protection in crossing flooded roads, their size and larger tires can make them more buoyant and more prone to being swept away. Bottom Line: It is just as dangerous to drive an SUV through flooded waters as a regular vehicle.

Some statistics to remember if you are ever faced with the decision of crossing a flooded roadway.
  • As little as one foot of water can move most cars off the road.
  • Just six inches of fast-moving flood water can sweep a person off his or her feet.
  • Most flood-related deaths occur at night and are vehicular.
  • Urban and small stream flash floods often occur in less than one hour.
  • Tropical cyclones pose significant risk well inland due to fresh water flooding