The number of alcohol-related traffic deaths has dropped significantly, indicating the success of new state laws and campaigns to reduce drunken driving, federal researchers said.

The proportion of traffic deaths attributed to alcohol decreased for all four age groups in National Highway Traffic Safety Administration surveys from 1982 to 1989, the federal Centers for Disease Control said Thursday.The biggest drop was recorded for drivers 15 to 17. In that age group, the percentage of alcohol-related traffic fatalities dropped from 31.5 percent in 1982 to 18.9 percent in 1989.

The decrease occurred even though the number of youthful drivers and miles driven increased substantially from 1982 to 1989, said Julie Russell, a CDC epidemiologist. There were decreases of 22 percent for those aged 18 to 20, 7 percent for drivers 21 to 24 and 11 percent for those over 25, the CDC said.

"The number of alcohol-related traffic deaths is going down for all groups," Russell said. "But they're going down most dramatically for the 15- to 17-year-olds."

In 1982, there were 10,000 alcohol-related traffic deaths for people ages 15 to 24, she said. By 1989, that number had dropped close to 7, 000, she said.

"I think public concern over this problem has caused things to happen. I think groups like Mothers Against Drunk Driving and Students Against Drunk Driving have helped bring about this change," she said.

The drinking age was increased to 21 in all 50 states and the District of Columbia, and there have been highly successful educational efforts and changes in state laws penalizing drivers under 21 for driving impaired, the CDC said.