COLUMBIA - Fewer state troopers and a change in the law that makes it more difficult to prosecute drunken drivers has led to a sharp decrease in the number of people arrested for drinking and driving, law enforcement officials and others say.

According to the Highway Patrol, arrests for driving under the influence dropped to about 7,400 last year, down from more than 10,000 in 2001.

Troopers make the majority of drunken-driving arrests.

The State Law Enforcement Division reported a similar drop among all police agencies statewide - there were 9,200 total drunken driving arrests in 2004, compared to more than 14,000 in 2000. SLED figures for 2005 were not yet available.

During that same period, South Carolina was among the top five states for percentage of fatal wrecks that involved drunken drivers, according to the most recent figures from the National Highway Traffic Safety Administration.

Almost 30 percent of drivers involved in fatal crashes in those years had blood-alcohol levels above the legal limit of 0.08 percent.

"We have nowhere to go but up," said Jami Goldman, executive director of the state chapter of Mothers Against Drunk Driving. "I'd like to feel safer driving on the roads."

Highway Patrol Commander Russell Roark attributes the drop in arrests to a 15 percent decrease in the number of troopers since 2001.

During that period, the total number of citations issued by troopers dropped 43 percent, but the number of collisions troopers had to handle increased slightly.

Last year lawmakers approved 100 new troopers, and another 100 are expected to be approved this year. That would put staffing near 2001 levels. "We are on the road to recovery," he said. "It's just going to take a little while to do it."

More troopers may not be the only answer. Victim's advocates say loopholes in state law discourage officers from making drunken-driving arrests.

"What's taking place in our state is that the officers are placed on trial, not the defendants," said Laura Hudson, spokeswoman for the South Carolina Victim Assistance Network.

Hudson says as part of the law changes that made a blood-alcohol level of 0.08 percent or higher the threshold for drunken driving, officers were required to inform people of their rights several times during an arrest, and to videotape the arrest and breath testing.

But if a case is prosecuted under an older law, police say, it's easier to get a conviction.

"It's almost as if the state of South Carolina is ashamed to prosecute DUIs," said Jeff Moore, executive director of the state Sheriff's Association.

Richland County Chief Magistrate William Womble said the newer law doesn't have major loopholes if officers follow the rules.

"If you absolutely follow the law, you can successfully prosecute," Womble said.

He said fewer arrests may mean that public education programs aimed at reducing drunken driving might be working.