Forty-three persons were arrested Friday night and early yesterday and charged with drunk driving after they were stopped by D.C. police operating the District's first drunk driving checkpoints.

During the 4 1/2-hour operation that began at 10:30 p.m. Friday, police stopped a total of more than 500 cars as they traveled east on New York Avenue NE near 16th Street NE.

Traffic backed up more than a mile in the three eastbound lanes and drivers caught in the snarl complained that they were tied up for more than an hour in the muggy weather. Many cars overheated.

Robert M. Goldstein, director of the police Alcohol Countermeasures and Traffic Services, who said he was surprised at the large number of arrests, said that the location was chosen, in part, because 10 percent of all recent alcohol-related traffic deaths have occurred at night on New York Avenue NE.

Studies show that 8 p.m. to 3 a.m. on Thursdays, Fridays and Saturdays are prime times for drunk driving, police said.

"Last year, we set the record for the lowest number of traffic fatalities in the recorded history of D.C.," Goldstein said. "There were 36 deaths, 14 of them alcohol-related."

This year the District already has recorded 20 alcohol-related traffic deaths, he said.

Police plan to set up roadblocks in every quadrangle of the city by summer's end, Goldstein said, adding, "The goal is to put a statement out to the public: We're going to get tougher on drunk driving."

Another police official said that the Friday-Saturday roadblocks were just a warning.

"If you're going to drink, don't drive," he said. "If you're going to drive, don't drink . . . . Drunk drivers . . . kill innocent people."

As cars were stopped Friday night and yesterday morning, the officers looked for such telltale sales as red eye or slurred speech. Those whom police thought might have been drinking were ordered to breathe into an electronic device that detects the presence of alcohol in the air.

If no alcohol was detected, the driver was given literature on drunk driving and allowed to drive on. If alcohol was detected, the driver was tested with a "roadside breath-tester." Under D.C. law, any driver with a blood-alcohol level of .05 is presumed drunk; drivers with a blood-alcohol level of .10 are considered legally drunk and no other evidence is need for conviction.

The series of roadblocks, officially called "drunk-driving checkpoints," was similar to last year's "sobriety roadblocks" in Maryland and Virginia suburbs.

Last Christmas weekend, Maryland State Police stopped 2,000 cars and arrested four drivers for drunk driving. One police official said then that the low number of arrests was "a sign that awareness of drunk driving is working."

Several drivers arrested for drunk driving at the roadblocks insisted that they were not intoxicated.

Irving James, 50, of Lanham, explaining that he had been to dinner at a popular seafood restaurant in Southwest Washington, said: "I only drank what I considered the norm after having a meal."

He was charged with driving while under the influence of alcohol and was released, but his car was impounded because he refused to take a sobriety test, police said.

"I feel that I didn't create a hazard," James said.

Standing on the corner, he watched with amazement as police let several hundred cars go by unchecked in order to shorten the lines of traffic caused by the roadblock.

Half an hour earlier, James had been flagged down while trying to drive through the same intersection.

"Look at all the people going by," he said. "I was the one they stopped."

Another unlucky driver appeared to have been attending a gala. Wearing a tuxedo, he followed Police Officer Arthur Pember's instructions to assume the stance of a tightrope performer and walk a line on the sidewalk.

"One, two, three, four, five," the motorist counted as he carefully placed one foot in front of the other. Next, asked to raise his right foot in the air and hold his balance, he counted: "1,001, 1,002, 1,003 . . . . "

But when the man lost his balance the officer arrested him and charged him with driving while under the influence of alcohol.