Keep a close eye on your designated driver this weekend, a new study found more than one-third admitted to putting back drinks themselves -- nearly 20-percent said they became too drunk to drive.

John McNamee with Mothers Against Drunk Driving Southeast Texas calls the numbers horrifying.

“Someone who is going to be the designated driver needs to take it very seriously,” McNamee tells KTRH News.  “Your friends and family whom you've agreed to be the designated driver are trusting you to be responsible and do the right thing.”

“Over 10,000 people a year die, Harris County leads the nation in alcohol-related fatalities,” he says.  “Being a designated driver is an important job.”

Despite this study, McNamee insists MADD's own surveys have shown designated drivers have reduced the number of alcohol fatalities by 40-percent each year. 

He points out two-thirds of respondents in this recent study did not have anything to drink.

“Drunk driving is a choice, and if you choose to drive drunk you've made that choice, the people around you did not,” he says.  “The cost could be terrible.”