Let me confess, right off the bat, that I am a person who lives only two blocks from the subway - yet I drive to work nearly every day of my life.

I fervently want the subway to Be There, for the days when the car or the weather breaks down. But I am delighted that those days are rare.

You see, I believe in mass transportation the way I believe in yearly medical checkups and wills. I am utterly convinced that it is the correct, sensible thing. I heartily recommend it to my friends. I endorse it to my government. And I avoid it whenever possible.

I confess all this sordid stuff now, because the Department of Transportation recently released its survey of commuters in 21 metropolitan areas. It turns out that two out of three of these people also drive to work alone. Only 17 percent of them are in car pools, and only 12 percent use public transportation.

So, it turns out that I am your better, basic, solo urban commuter - with only guilt as my copilot.

I am precisely the sort of person the government has spent years trying to persuade to ride the rails or sign up for pools. And, as a statistic of failure. I want to do my patriotic bit by explaining.

I think the majority of us drive not because (as it usually assumed) we find car pools and subways so horribly inconvenient. There is, after all, nothing especially convenient about wending through the "creep and beep," "stall and crawl" rush hour on city streets.

Nor do we drive solely, as Ed Diamond suggested in Esquire magazine, because "what people really want is the freedom to move about at will." How can we move about when all those around us are stalled at a traffic light?

We drive because we really want the freedom to move about at will . . . Alone.

The car and the subway come with matching horror stories - one traffic jam for every stalled train, one overturned truck for every power-out. We fundamentally choose wheels for the same reason Greta Garbo chose sunglasses. Ve vant to be alone.

We prefer the private hassles to the public ones, and the illusion of control to the feeling of being controlled. But more than anything else, the automobile is our isolation booth, our own piece of solitary confinement, our daily dip in the water-immersion tank.

The car is the one place the average urban dweller can find without a television, a telephone, or tension, with no more busywork than a clutch or a brake, nothing to read except a street sign. And with nobody else to talk to.

It's our think space, where we do our best hope and mourning, fantasizing and raging, on semi-automatic pilot. At any red light, we can be seen moving our lips through the pivotal scenes of our lives, shuffling the cast of characters and the script until, at last, it comes out right.

I suspect that one-third of all commuters spend their drive-time figuring out what they Should Say; another one-third figuring out what they Should Have Said. The last third plan perfect dinner parties and tennis serves, memos and love affairs.

For all the aggravation of Demolition Derby driving, there is still a sense of saneness that comes from spending a half-hour or so in a private space. You can find that same sensation on a subway only if you are deeply into yoga.

Mass transportation is for people, yes; but I'm afraid that the pollutant on four wheels is for a person. Until they turn the subways into isolation booths, or separate us with magnetic-field suits, I think most of us will choose to go on paying through the hose - for a mobile room of our own.