COLORADO SPRINGS, Colo. -

Law enforcement agencies throughout southern Colorado are keeping a watchful eye on the roads for impaired drivers this New Year's Eve.

It's not just drunk drivers they're on the lookout for, but also stoned drivers. The start of the new year means recreational pot sales will begin.

"Is there a possibility that there's going to be an increased number of instances where a driver has in fact used marijuana because it is more readily available, things of that nature? That's certainly a possibility," Lt. Jeff Kramer, with the El Paso County Sheriff's Office said.

Kramer and other officials say it's too early to know for sure if recreational pot sales will increase marijuana-impaired driving. But they are ready to catch those impaired drivers who get behind the wheel.

Colorado State Patrol said troopers are well-trained to spot impaired drivers, including those under the influence of marijuana.

"They're going to be looking for certain signs and symptoms related to marijuana," Corporal Christopher Grimsley said. "Things like pinkish eyes, dilated pupils, and then certain psychological symptoms such as confusion and paranoia."

Grimsley said if necessary, the suspected impaired driver will go through a series of voluntary maneuvers to detect the presence of marijuana or other drugs, and possibly also blood testing. But drivers can avoid the process all together by following the law.

"Even though marijuana has been legalized for possession here in the state of Colorado, it is still illegal to drive under the influence of marijuana," Grimsley said.