Re: "Radar Cameras Set for Debut on Beltway" {Metro, June 17}: Why is it that many among those who clamor against the use of photo radar on the Beltway are the same people who defend the use of television surveillance in their banks because "the cameras contribute to my safety"? THEODORE J. COHEN Alexandria

In approving sobriety checkpoints, this Supreme Court has really jumped headlong into judicial activism. Since when does the magnitude of a problem, such as drunk driving, outweigh our Fourth Amendment right against unreasonable searches and seizures? My copy of Amendment IV reads, in part, "The right of the people to be secure in their person, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated. . . . " It does not make exceptions for problems of great magnitude or for privacy intrusions that are only minor. The Bill of Rights as a whole supports the principle that the ends do not justify the means.

So what can we do to stop the carnage from drunk driving while protecting our constitutional rights? Fortunately, we now have the technology to equip all cars with computers that can control the ignition. A person would have to pass a short test of cognitive functioning and reaction time in order to start a car. This would be far more effective in stopping drunk and drugged drivers; it would stop perhaps as many as 99 percent of them instead of the one percent caught at sobriety checkpoints. It would have the added benefits of getting drivers off our roads who are too tired, too emotionally upset or too uncoordinated from antihistamines or other medicines to operate a motor vehicle safely.

Sure, it would add to the cost of every car, but isn't it worth it? BETTY KING Alexandria