My role in the family is to take well-conceived vacation plans and complicate them. Someone in every family has to be the acknowledged enforcer of the laws of entropy. Over the years, I have had a gift for turning even the most sublime vacation into an ordeal. Thus, almost from the moment we arrived at de Gaulle for a vacation in Paris, I began dreaming of leaving Paris behind and going on a road trip.

I wanted to see castles and vineyards and tiny French villages with cobbled streets barely wide enough for a tank. (For many American males of a certain age, old European streets are inevitably associated with tanks, from watching TV shows like "Combat.") But I didn't know if a road trip would be plausible in France — a real road trip, the kind that's impulsive and potentially calamitous. The authentic American road trip is not just a means of getting from Point A to Point B, because Point B is often an unknown. A road trip should have something of the feel of a jailbreak.

The United States has the infrastructure to support such spontaneity. You can pull off the highway, grab chow, spend the night, hit the road again. These freeway-exit retail villages have no character, of course, and at 3 in the morning it is impossible to recall if you're in a Comfort Inn or a Motel 6. But it doesn't matter. The great virtue of these places is the ease with which they can be departed.

Could that style of travel be transposed onto the continent of Europe, with its fetishization of mom-and-pop hotels and its little country inns and its presumption that travel should have some stickiness to it, some odd textures and quirks and eccentricities that don't lend themselves to drive-by tourism?

Obviously a person can, with some forethought, drive just about anywhere in France or elsewhere in Europe, because there are cars, there are highways, there are gas stations, etc. This is not like parachuting into Siberia and trying to use a hand ax to build a raft to float down the Lena.

But you don't hear of many Americans doing European road trips, because they prefer to travel by rail. Indeed, you'd think they were required to, that it was a law laid down at the same time as the Magna Carta.

My colleagues and friends warned me that renting a car and driving in France would be problematic. They pointed out that the cars can be expensive and tiny, and that gas is so precious it is sold by the liter, as though it were wine. Lodging could be iffy since, at the end of July and early August, everyone in Europe goes on holiday. "There are stories of people sleeping in their cars along the highway," a veteran Paris correspondent warned me.

My wife, moreover, is the kind of person who does not believe that travel requires compulsive motion. She had carefully planned our trip to Paris, and considered it sufficiently reckless that we were crossing the Atlantic without first learning French. She packed a library of books about Paris. We were ensconced in a house about a block from the Eiffel Tower. A road trip would surely be a fiasco. Worst of all, we'd be immersed in uncertainties and unknowns.

I responded to these concerns as any husband on vacation would, with calculated indecision and paralysis, and for two weeks, we enjoyed the Paris life and filled up on baguettes and took in museums, until one Friday night I could take no more, and got online and booked a car for the next morning. Road trip!

DAY 1

There is skepticism in the Eiffel house about whether we are actually going. But we are. It is imperative to nip in the bud any incipient revolt that might nix the excursion.

I do something smart, if I may say so: I pick a destination, the Loire Valley, and search online for rooms in that vicinity. I pick the Loire because it has castles and is a couple of hours away and it sounds like an authentic destination (more so than "Let's go south"). I search in Orleans and Angers and finally find two rooms in a hotel in Tours. It's a Comfort Hotel. Yes, the Comfort Inn! Same chain!

I recognize that purists would be horrified by such a decision. But certainty and reliability have their charm. I can sell the concept of the Comfort Hotel. Sleeping in the car has now been removed as a potential item in our itinerary.

Next step, get the car. I have to go back to the airport, de Gaulle. (I've got a rate of just $217 for four days, though at one point they tried to stick me with a rate of $529. They backed down.) The journey to de Gaulle on the RER train takes forever, and then I go to the wrong terminal, and when I finally find the Europcar counter it is besieged by a mob of Englishmen. A single employee stands behind the desk. The queue doesn't move. I cannot suppress the thought that, although Europe has fabulous museums and cathedrals, in America we have some rather sublime rental-car facilities.

One of the Brits finally succeeds in renting a car and shouts "Got keys!" as he runs down the concourse. In the course of the next hour and 15 minutes, I have plenty of time to contemplate the downside to being a spontaneous person.

Eventually I get the car, a Ford "Foo-kus," as the agent puts it. An hour later, I'm back in Paris proper, and after loading up the family, we're on the road, heading south on the A10.

Two hours later, we're in the Loire Valley, walking toward a humdinger of a castle.

The valley is lousy with these chateaus, and this one, Chambord, is perhaps the biggest, most ostentatious, in some ways least approachable, for it is parked in a vast wildlife preserve, isolated in space and time.

The brochure informs me that Francis I had it built in the early 1500s, though it wasn't finished until Louis XIV did his Sun King magic the following century. The thing is impossible to look at without thinking of Cinderella's castle. It definitely could use a roller coaster and maybe a flume ride.

I buy a map in the gift shop and look, in vain, for some kind of Guide to France.

Evidently people who make it this far have already got one.

The map, however, helps us negotiate the villages that line the Loire River. On both sides there is a levee, on top of which a two-lane road is a motorist's dream. We pass more castles looming on the bluff. We drive through Vouvray, a white-wine mecca, and my spirits soar as though I'd just had a carafe. Wine country! Who knew?

We eat in downtown Tours in an Italian restaurant, and my wife and I pop into an English pub where the bartender says the locals speak the most perfect French in the entire country. Pearls before swine, in our case, but it's nice to know that all those words we can't understand are beautifully articulated.

The motel, we discover late in the evening, is not the Ritz. It is not even the Ritz Express.

But it's clean, the staff is friendly and the price — about $150 for two rooms, not including breakfast — isn't bad. On a spontaneous road trip, every man's motel is his castle.

DAY 2

We wake up and decide that awful as it is, we'll stay a second night at the Comfort Hotel and explore the castle country by driving more or less in circles.

We stop for coffee in a hole-in-the-wall along the Loire. We pop into a wine cave and purchase a bottle. We go to Chenonceau, a castle built on the Cher River with the water flowing underneath. There are formal gardens and a 16th-century farm. The castle could use a TV room with a plasma screen, but otherwise you could throw some killer keggers at the place.

We drive off to Amboise, where there's another castle, and then we see more castles as we drive all over the place, and eventually wind up back in the old section of Tours, eating at an Irish pizzeria. It's good. I'm guessing that the guidebooks have overlooked this local treasure. A great day, all around.

DAY 3

A bad day. Everything goes a little bit wrong.

We drive 125 miles north, through Normandy, where imagining tanks on narrow village streets is by no means a stretch. But our objective, the beach at Deauville, turns out to be a longer drive than I had anticipated. Distances are hard to gauge in Europe: A two-hour drive turns out to be, when you do it, more like four. And at the gas pump, you just have to avert your gaze from the price.

Deauville itself is quirky, more English than French in its architecture. We just miss the public market, and a lot of stores seem to have been shuttered, and the beach is a little disappointing.

There are murmurings about returning to Paris. I douse that notion and drag everyone to Rouen, which I think is 30 minutes away but is more like an hour. I've found, online, yet another Comfort Hotel. It's like a bad habit I can't shake. This hotel is in a part of the city that shuts down at 7 p.m. There is litter all over the pedestrian mall, and panhandlers. We walk across the Seine to the cathedral that Monet loved to paint.

After we walk back to the hotel, we discover that we just missed a light show at the cathedral. The guy in charge of this road trip is clearly an idiot.

DAY 4

I've lost my audience. We go home. We do not even stop and see Giverny along the way.

So can you do a road trip in France? Yes.

The motoring is excellent. The roads are in many cases delightful. We will always remember the castles of the Loire.

Road-tripping might not be a great idea if you're a nervous driver. There are signs you can't understand, roundabouts instead of traffic lights, not enough parking and so on. You don't want to have to deal with these uncertainties while being already unnerved by driving a stick shift.

Reluctantly, I concede that there are virtues to planning. There comes a moment when you realize that improvisational motoring is really not so different from being lost. Freedom's just another word for not knowing which way to go.