IN CASE YOU missed the story in this paper the other day, take note that it's now illegal to drive in Washington or ride in the front seat without your seat belt on. The District's seat belt law, which was passed by the D.C. Council and signed into law by Mayor Barry last October, has been in effect since Dec. 12.

The law provides for a $15 fine for anyone in the front seat of a car who hasn't buckled up, but it isn't really being enforced yet, and won't be for a while. Before the police start issuing tickets, there is to be a six-month "education" period during which the District government will seek to get out the word to the public on the law and its purposes: to save lives and prevent or lessen injuries.

That seat belts do all these things is not really in doubt anymore. The main argument is over whether a significant portion of the population can be persuaded to buckle up. Many of those who doubt that persuasion and coercion will ever work say that cars must be equipped with passive restraints, such as air bags. The federal Department of Transportation has, in fact, mandated such restraints for the future. But the DOT regulation provides that if states containing two-thirds of the country's population adopt mandatory seat belt laws by 1989, the requirement won't take effect. That's why the auto companies are lobbying for seat belt laws in state legisla- tures.

The D.C. Council deliberately set the fine here so low that the law doesn't count toward that two- thirds goal. But even if passive restraints are required in new cars of the future, the people driving today's automobiles need to make use of the considerable protections they already have. Maryland legislators should take this argument into account when they consider a seat belt law in their next session.

Under the new D.C. law, you can't be stopped by the police for failing to buckle up; you can be citedring with some of his work.