SINCE THE FIRST of the year, more than 2,000 motorists have been arrested in Virginia for having radar-detection devices in their cars. This has caused a bit of an uproar among those who use, and love, these electronic marvels - in particular, out-of-state drivers who have unwittingly fallen into the hands of the highway patrol. And it has even led the executive director of the National Drivers Association to describe the law that bars these devices from automobiles as "outrageous." We would like to say a few words in defense of the law and to apply that adjective - outrageous - to the protests against it.

The Virginia law makes possession of a radar detector punishable by a fine of up to $100 and a jail term of up to 10 days. It also provides for confiscation of the device by the state, not a small penalty in itself. The legislation was passed at the urging of the state police, who know these detectors are used solely to give motorists advance warning of when they might be caught exceeding the speed limit.

Although the objections to this law are cast in terms of how it deprives motorists of a basic right, the only thing it really deprives them of is a tool designed to help them commit a crime and escape. Radar detectors, unlike CB radios that can be used for the same purpose, have only one reason to exist in automobiles. That is to let their owners speed with impunity. Of course, that's just what their owners want to do. They apparently do not think of speeding as a crime but regard it, instead, as a game they play with police. To them, a radar detector is just another way of getting an edge in that game. But speeding is a crime. And it is a crime that results in more deaths in this country each year than any other crime. Somehow, we doubt that anyone would describe as "outrageous" a law that prohibited the possession of a device whose only purpose was to warn murderers (or even burglars) of the approach of police.

It may be true, as some of the protestors claim, that this law runs afoul of the Communications Act of 1934 in which the federal government took over control of most of the airways. If that turns out to be true in court tests, Congress ought to amend the act promptly to authorize such legislation by the states. Even better, Congress ought to act now to bar the interstate sale of radar detectors for use in automobiles. They are, after all, instruments of crime. And, unlike even handguns, they have no other value.