Who says there aren't any places to park on the streets downtown? Take another look: people are finding places -- illegal places -- all over the streets. They just pull up alongside another car, hop out and go about their business. On a really good day, with fleets of limos and herds of delivery trucks grazing the lanes, double-parking is nothing; you'll see triples and quadruples. What's more, if you don't back off and out fast enough, you may end up joining the party for an indefinite stay. And heaven help those who may motor into one of downtown's narrower, one-way commercial streets, such as 19th NW, between Dupont Circle and K. There, nothing on wheels moves except maybe roller-skaters.

There's some perverse logic behind all this lane- clogging. Cars that are primly parked at curbside are constantly being ticketed by police and by those meter-minding scouts from the department of transportation, who double-park their own blue- dome-light cars when they move in for their kill. Double-parking is different because it seems to be mysteriously invisible to the law-enforcement eye. Besides, if anybody in authority ever asks, you can just say you thought the drug store had valet parking.

City officials have discovered one way to eliminate a lot of double-parking, at least fleetingly: ban single-parking on busy streets. That's what is going to start on weekend nights in Georgetown, effective tonight, along Wisconsin Avenue and M Street. A crackdown actually took place last weekend, largely because the congestion had been hampering crime control along these strips.

But all over town, the same authorities who are starting to get serious about ticketing red-light runners and jay-walkers might scribble up a few more windshield messages for those who seem to think that a parking spot is anywhere between two curbs.