SAN ANTONIO -

The typical black and white police car is hard to miss, but San Antonio police are also hoping to keep drivers in check with a fleet of barely-marked vehicles, which are designed to blend in with traffic to look for aggressive drivers.

San Antonio police Officer Chris Gates said that drivers on the highway who may be speeding or tailgating tend to revert to their best behavior when they see one of the traditional black and white police cars.

"Everyone is below the speed limit," said Gates. "Everyone uses their signals."

However, the San Antonio Police Department's Aggressive Driving Unit will soon introduce solid-colored vehicles with subdued markings to blend in with traffic.

Gates said when officers are on the highways, they can see what some of these drivers are doing when they don't think someone is watching them.

"You kind of watch (and) try to figure what people's habits are," said Gates. "The people that are impatient, you can see them zigging back and forth."

San Antonio police officials said for those who may think these cars may be confusing to drivers, this story is a fair warning.

They want the public to know they are out there on San Antonio highways and they are using 15 of these vehicles, which include a Dodge Charger, a Chevy Tahoe and a Ford Mustang.

Gates said if you get pulled over by one of these vehicles, you should acknowledge that officer.

"A lot of people, they'll acknowledge that they recognize us behind them, they'll wave their hand or they'll turn on their hazard lights, something like that," said Gates.

Last year, the aggressive driving unit issued more than 4,700 citations, mostly to drivers following too closely, speeding or changing lanes without signaling.

"People need to make driving their priority, said Gates. "Not everything else that they're doing -- texting on their phone, curling their hair, reading the newspaper, whatever it is. It's just a matter of time. You're going to get caught. We're not out here to ruin days. We're here to save lives."

Click here for the San Antonio Police Department video on what to do if you are pulled over by a non-traditional officer or an unmarked car.

For a list of recent stories Stephanie Serna has done, click here.