Hurricane Harvey: why you should never drive on flooded roads

Hurricane Harvey is posing an unprecedented, catastrophic flood risk to Texas. As of Sunday morning, it had downgraded to a tropical storm. But it’s the storm surge and rains Harvey will continue to bring to the Texas coast that will cause the most destruction to life and property. Already two people are reported dead and up to are 14 injured, with significant damage to buildings and trees.

Right now, emergency managers are advising many coastal communities in the storm’s path to stay put — because once roads are flooded, driving actually becomes one of the most dangerous things you can do. Most people who die in heavy flooding, it turns out, die in their cars.

Almost two out of every three flood-related deaths between 1995 and 2010 (not including Hurricane Katrina) occurred in motor vehicles, according to Greg Forbes, a severe weather expert for the Weather Channel. Here’s how that happens.

These conditions can cause fatal accidents on their own but can also lead to (horrifically) drivers or passengers drowning while trapped in or attempting to escape their vehicles.

“As little as six inches of water may cause you to lose control of your vehicle,” warns the Centers for Disease Control and Prevention (CDC). Not to mention, two feet of water — or one foot of fast-moving water — can sweep away most cars, according to the CDC and the Department of Homeland Security.

A 2003 study in Traffic Injury Prevention found that many of the people who died in 1999’s Hurricane Floyd had received warnings but still either deliberately drove into flooded roadways anyway or unexpectedly encountered flooded roadways while driving in severe-weather-affected areas.

And even in 2016, after Hurricane Matthew, a CDC mortality surveillance report found that repeated public health warnings still resulted in drowning associated with a motor vehicle as the most common cause of death.

The best advice, according to the Weather Channel, is to never drive when you don’t know how deep water is. And if the water is covering the surface, you probably don’t know how deep it is. It’s easy to misjudge the depth of water, they say, especially at night.

Recently, in response to Hurricane Harvey, the National Weather Service, FEMA, and other local and federal government officials and departments have been pushing the message “turn around, don’t drown” on Twitter to discourage people from driving on flooded roads.

If you’re in the affected region, please heed their advice.