The lights flash by Marietta Police Officer David Auld's darkened patrol car, which sits along I-75 as if crouched, ready to spring. Auld is using a handheld laser device to check the speed of the cars whizzing by, their drivers anxious to get home after a long day at work.

A black Toyota sedan flashes past at 84 miles per hour, 19 mph over the speed limit.

"We'll go get him," Auld says, jumping into his patrol car and throwing it into gear. The engine revs mightily as he pulls from the shoulder into traffic. He hits a couple of toggle switches and the whole world around him is illuminated in flashes of blue light.

Auld is assigned to the department's HEAT unit – Highway Enforcement of Aggressive Traffic. Every night from 8:00 p.m. until 4:00 a.m., his job is to find speeders and those who drive impaired or over-aggressively and stop them before they hurt themselves or someone else.

It is a job that is perhaps never more important as now. In 2013 to date, 18 people have died on Georgia interstates, compared to 12 people during the same period a year earlier. That is an increase of 50-percent. The number of people killed in accidents on Georgia state roads during the same time this year jumped 144-percent compared to the same time last year.

For Officer Auld, those statistics carry an all too human toll.

"I don't want to have to be the one who stands on someone's doorstep at two, three or four o'clock in the morning," he said from the seat of his stealthy-looking cruiser. "I don't want to have to wake them up and tell them someone they love is never coming home again. I've had to do it way too often. I hate that."

This time, the errant driver on I-75 near the Canton Road Extension gets off with just a warning and a lecture.

"These luxury cars are easy to drive," he tells the sheepish driver who seems as if he is trying to disappear into the driver's seat of that black Toyota. "But that sudden stop gets everyone. Slow down and drive safely please. I'd appreciate it."

The speeder drives off, not knowing just how sincere Auld was in making that last statement.