COLUMBIA--South Carolina drivers who count on state troopers giving them a 10-mph speeding cushion could be right as some troopers say they use their discretion to pull over the most serious speeders.

Fewer troopers on the road led to a 7 percent drop in speeding tickets issued during the first half of this year compared with last year.

The state Department of Public Safety reported 66,671 speeding tickets written from January to June 2005, down from 71,647 for the same period in 2004.

Public Safety spokesman Sid Gaulden said the decline was because of fewer troopers on the road. A class of 28 troopers graduated Friday to bring the total statewide to 783. That's down from the 961 troopers who were on the road in 2000.

Those new troopers may have a lot to choose from when they head out on patrol.

Studies by AAA Carolinas show motorists in South Carolina, which leads the nation in speed-related traffic deaths, drive about 10 miles an hour over the speed limit on average because they think officers won't pull them over.

While there is no written policy, officers say they pick and choose who they pull over.

On a recent August evening, Lance Cpl. C.M. Coats of the South Carolina Highway Patrol parked his police cruiser under an overpass on Interstate 77, cut his lights off and had his pick of speeders.

All of the first 10 cars to pass him were going faster than the posted 60 mph speed limit. He chose to pull over the 11th car, though she was going no faster than two other speeders who went by at 80 mph.

"It's up to the officer," he said.

The woman was from Pennsylvania and told Coats she was trying to find Fort Jackson, but ended up in Charlotte, more than 80 miles away.

Coats reduced the charge to going 69 mph in a 60 mph zone.

Coats would not say whether he had a cushion that he allowed drivers before he pulled them over.

Roderick Bailey, traffic safety manager for AAA Carolinas and a former police officer, said officers do have limits, but they vary.

"I had my own limit," Bailey said, "and that changes throughout the day on that same highway."

Bailey said he would stop motorists driving 10 mph over the speed limit, but during high traffic times, such as rush hour, he would reduce that to 8 mph over.

On weekends, meanwhile, he might allow a driver to go 14 mph or more over the limit.

He said writing a ticket for driving 1 mph over the speed limit would "look pretty stupid in court, so it's the reason people do what they do."

LaShawn Pendergrass of Kingstree said she feels comfortable at 7 miles over the speed limit but will increase that to 10 mph over on interstates that have a 60 mph limit.

Esther Kramer of Columbia said she is a consistent speeder but uses her cruise control to keep herself at no more than 7 miles an hour over the limit.

"That's absolutely critical for me," she said. "I'm not as nervous about police officers because I'm only going 7 miles over the speed limit."