Don't go looking for it on any public map or roadside signs, but a highway designated Interstate Rte. 695 suddenly has materialized in the District of Columbia.

I-695? In our region, we've got 95, 295, 395 and 495. The new one, 695, is part of what most of us call I-295, the section of the Southeast/Southwest Freeway between the Navy Yard interchange westward to the ramps that lead to the Third Street SW/NW tunnel beneath the Mall.

If Metro Scene were setting out to muddy the waters, the Third Street tunnel would be described here as the Center Leg of the Inner Loop Freeway -- but, heck, there's no desire here to obfuscate things by doing that.

To explain the I-695 complication, at least a little: Until now, most of us have considered I-295 as the freeway running all the way from the Capital Beltway at the east end of the Woodrow Wilson Bridge through the Navy Yard interchange to the Third Street tunnel ramps near the Capitol in Washington. But when the city had to assign a number to the short freeway spur from the Navy Yard interchange eastward to the Sousa Bridge, that was numbered I-295.

This left the westward link across the southern brow of Capitol Hill to the Third Street ramps nakedly without number. So the D.C. highway folks had to provide a number. Voila! I-695.

Two points:If you think the foregoing is hard to understand, think how hard it is to write this attempted explanation clearly. The entire matter was made necessary by a new federal law permitting two-trailer trucks. D.C. officials had to invent I-695 to give permission for such trucks to use it. Metro: 1; Taxis: 0

One of the nation's most respected travel writers, Horace Sutton, wrote about a recent visit to Washington. He praises our "clean, clean, clean" Metro system so effusively that even an avid supporter must blush. Among other things, he said that it "goes everywhere." Try Georgetown.

But his widely syndicated article as published recently in The Los Angeles Times and sent along by Metrophile Dick Steen, has some telling things to say about our taxicab system, which began rationally enough but is weird in its administration and enforcement, or lack thereof.

Calling the taxi system "kooky," Sutton said that "cabs come in all varieties, mostly including all D.C.-licensed units without meters, and are driven by cabbies who charge big bucks if you cross a zone line and the only one who knows whether you've done that is the guy behind the wheel."

In fairness, there are zone maps in each cab, but the rider must first know local geography.

"The ride to the Washington Hilton from National Airport, which is practically in the lap of the Pentagon, the other night cost $15 with tip. And a short jaunt from a restaurant hard by the Capitol to the door of the Capital Hilton, which almost looks into the White House (it's three blocks north), was calculated at $4.50 before the tip."

Sounds costly, but one would have to know how many people were in the party.

In any event, Sutton is only the latest of a series of travel writers urging visitors to ride Metro.

Except, of course, after 6 p.m. Sunday, when Metro turns into a pumpkin.