REVELERS leaving Georgetown in the small hours last Saturday morning had what police hope will be a sobering experience for the future. Hundreds of drivers were stopped by officers at a roadblock on Canal Road, and 39 of them were arrested on drunk-driving charges.

The Canal Road checkpoint and a similar effort conducted on New York Avenue in June are part of an intensified effort by D.C. police, prompted by the recent sharp increase in alcohol-related fatalities. Drunk drivers have already killed 22 people in the District this year, more than three times the number killed during the same period a year ago. But the strong support that the public has given to anti-drunk-driving measures in this and other jurisdictions shows that the country has, at long last, outgrown its tolerance for this most common and dangerous type of crime.

Checkpoints are, of course, an inconvenience to the many innocent motorists who must necessarily be stopped. But, as they have been prudently operated in the District and surrounding jurisdictions, that's all they have been--an inconvenience. Most drivers accept the measure as a small price to pay for keeping potential killers off the road. Police questionnaires returned by motorists stopped on New York Avenue registered an 88 percent approval rating.

The politeness and evenhandness with which the police and other law-enforcement officials have generally been conducting their anti-drunk-driving efforts are the key to maintaining public support. Montgomery County police made a start in the wrong direction last March when they initially failed to press charges against Rep. Louis Stokes when he failed roadside sobriety tests. The police mistakenly believed that the congressman was immune from arrest on a criminal charge, although, as they later admitted, Rep. Stokes made no such claim. A Montgomery County jury, by the way, has now found Mr. Stokes guilty of driving while under the influence of alcohol, but not guilty of the more serious charge of driving while intoxicated. They seem to have made a very careful and precise judgment.

As a general matter, it is too bad that responsible motorists have to be inconvenienced because so many of their fellow citizens lack the common sense to keep away from the wheel when they have been drinking. But the simple fact--supported by years of ugly statistics on alcohol-related fatalities--is that common sense, at least applied in this area, is not in sufficient supply on American roads. The only effective deterrent to this most common violent crime is the strong, sure and impartial enforcement of driving laws.