IF 'TIS THE SEASON to feel guilty, as the psychologists tell us, I've got a whopping case to report. I haven't looked forward to a Christmas season so much since I was 6 years old.

And the reason is I-66.

Spare me the bleats about the way the highway is ruining neighborhoods from the Beltway to the Potomac. I know. This is why I'm feeling so guilty.

Spare me the arguments that I shouldn't engage in a 11/2-half gallon, one-hour, one- way commute from the foothills of the Blue Ridge into the District, anyway. A man who can rationalize living with cattle, hogs, sheep, goats, geese, chickens and rabbits can rationalize anything.

Spare me the snide observations that I-66 will cut a grand total of six minutes off my non-rush-hour drive. I know that intellectually, just as surely as I knew 28 years ago that it was totally impossible for an elf who lived north of Prudhoe Bay to squeeze down several billion chimneys worldwide in one night.

But the fact remains that for years I've been driving by all this construction that tantilizingly ended at the Beltway. Now it is about to bear fruit. And I'm stuck with this irrational reality. I haven't been so much in the Christmas spirit since I counted the days in anticipation of my first set of American Flyer trains.

In 1954, when I was 6, the countdown was marked by my hometown paper. Every evening, above the masthead, my expectations were heightened by the graphics announcing the days left to Christmas.

In 1982, the countdown was marked by heavy equipment. Every morning, as I drove into work, I watched them install the graphics of my new Christmas present. The imposingly cryptic HOV-4 signs looked like a hi- tech gift from the wise men of the California Highway Patrol. The traffic jams caused by the men laying the new lane markers aimed straight for downtown enflamed my sense of anticipation. The street-sweepers clearing the roadsalt of the ages from the asphalt only now to be used, might as well have been polishing crystal Christmas tree ornaments for the effect it had on me.

The days dwindled down.

Almost sadly I bid adieu to the high-speed merge onto the Beltway where, every day of my recent life, I had faced the thrill of wondering whether I would finally meet the tractor-trailer with my name on it.

With aplomb I passed the signs that I never had really understood, explaining which way traffic was supposed to go on Chain Bridge.

Gleefully I clocked the duration of the last traffic jam I hope I will ever face as the George Washington Parkway narrows down to one lane at Spout Run.

I know -- $275 million, for a measly 10.1 miles of road. One of the most expensive stretches of Interstate in the history of the Republic. Truer words were never spoken: The difference between boys and men is the price of their toys.

I can't justify it. All I can do is report it. Maybe it's the thrill, for the first time in recent memory, of actually, personally, and selfishly seeing my tax dollars at work in a way that I can use. I simply haven't been able to see this thing as a road and a social blight, although I know I should.

I've only been able to see it as a Christmas present to that battered and unloved part of me that spends so much of its time behind a steering wheel. Maybe it's the sense of orphanhood that we long-haul drivers all share that's responding. Amid the usual winter tribulations, I reach to this road as if it were a second helping of gruel.

Whatever prompts my outpouring of season's cheer, I simply can't deny that it exists.

Thank you, Uncle Santa. Merry Christmas to me.

P.S. When do I get my Metro stop?