Tourists not wise to the ways of Washington are hereby warned to turn to the furniture ads.

Honest, folks: It's for your own good. You simply won't understand the following item. But oh, how we Washingtonians will.

From Maureen Marlowe of Alexandria came the original question:

"Why redo the electrical system at the White House and close East Executive Avenue at exactly the time of year when the largest number of people want to use it?"

The answer, from George Berklacy of the National Park Service:

"It's a $2 million job, and when you're talking about that kind of money, you pretty much have to start the work as soon as the funds become available. Congress made them available starting in March, so we could hardly wait until September. They'd be raising hell up there."

Which is exactly what's being raised in the meantime by Joe and Martha Instamatic, who drove for three days from East Kankakee just to get a quick, motorized look at the East Gate of Mr. Reagan's house.

It was all preventable, too. The Appropriations Committee members who approved the White House wiring probably never considered the effect on traffic and tourism.

The Park Service should have made it a point to make it a point.

Being a linear-minded soul, I have always found it difficult to understand why changing C will have a positive effect on A or B. But that's exactly what's happened, according to William J. Carlson, at the always-madness intersection of Connecticut Avenue, Jones Bridge Road and Kensington Parkway in North Chevy Chase.

For 20 years, or since the Beltway was built, traffic trying to go south from the Beltway onto Connecticut and east onto the Beltway from Connecticut has had to use a half-mile long stretch of tree-lined, bucolic Kensington Parkway.

It's been a mess.

Despite its wide-sounding name, the two-lane parkway was designed for Sunday strolls and kids on tricycles. It simply hasn't been able to handle a daily dose of superhighway traffic. Half-mile-long backups along it as cars waited for the signal at Connecticut and Jones Bridge have been common.

But on May 11, Carlson, an assistant district traffic engineer for the State Highway Administration, ordered an end to both southbound and northbound left turns from Connecticut onto Jones Bridge.

The result? Much smoother traffic flow on Kensington. The reason? The green-light time formerly taken up by all those left turns has now been given to Kensington.

"It has already improved things a great deal," Carlson said. "We expect to soothe a lot of savage beasts in North Chevy Chase."

Let's hope so. It's high time.

"I don't believe it," I told Joan Lewis.

"Try it," she urged me. "No one believes it till they try it."

So I drove across Teddy Roosevelt Bridge from the Iwo Jima Memorial to 23rd Street and Constitution Avenue NW. -- a distance of two-fifths of a mile. Sure enough, in that paltry distance, the speed limit goes from 45 to 40 to 35 to 40 to 30 to 25.

Did you get them?

The five states' names that were never abbreviated before Zip Codes reduced every state to two letters are: Utah, Iowa, Ohio, Idaho and Maine.

With my usual promptness, let me salute John Wilson, Washington lawyer extraordinaire, who observed his 80th birthday on July 25.

Friends (and especially opposing counsel) will not be surprised to learn that Wilson celebrated No. 80 the same way he has celebrated so many others -- by putting in a long, bone-grinding day at the office.

"He looks terrific, and he's as active as ever," reports colleague Charles Steele. Here's to 80 more.