My family celebrated International Walk to School Month early — it’s in October, if you didn’t know, and I didn’t — by buying a car. Now, it’s Daddy Drives the Kids Home from School Month.

We’re not trying to be contrary. Walking to school is healthy. It would be nice if my kids could do it.

But that would take more than improving sidewalks or slowing down traffic, the usual prescriptions. Maybe taking away women’s career options would help, or demoting the middle class.

I don’t favor either, but let me explain: My children’s school lies about 10 miles from our house. Distance, say experts, is easily the common reason children don’t walk to school, a much bigger barrier than traffic. Schools are farther because people moved to suburbs and districts built fewer, bigger places, say the smart guys.

I’m sure they’re right, though none of it applies to us. We live in the middle of an old Great Lakes city. I can think of 11 school buildings within about a mile. Sidewalks lead to them all.

But not a one is a Catholic school, which is what we want. Three of them used to be. One was four blocks from our house. All have closed. The Italians and Irish and Poles for whose progeny those schools were built all aged. Their kids grew up, became the mainstream of America, and mostly moved to suburbia. The neighborhood’s pierced, hip, and childless newcomers don’t need Catholic schools.

Besides, who’d teach in them? Nuns, whose vows of poverty kept tuition affordable, are considerably rarer these days, now that bright Catholic girls have so many other opportunities. So tuition’s costly, fewer families afford it, and schools merge to stay viable.

For my kids to walk to school, then, you’d have to reconstitute the glory years of the neighborhood Catholic school, something that sadly faded because of a generally laudable thing — the coming of broader horizons for the Catholic working class. If you could undo that, we might have nuns at the chalkboard and a neighborhood full of 10-kid families, but I’m pretty sure most people would be unhappy. Their choices show that this isn’t what they want.

Limiting choice is on all kinds of agendas. Mention the walk to school and you’ll soon have someone ranting about urban sprawl. Every burg in Wisconsin must, by law, come up with a “smart growth” plan on the premise we’re running out of land, though all the cities, towns, suburbs, hamlets, and every other kind of sprawl together take up only 7% of the state.

No matter: Because buyers favor yard sizes that irritate planners and environmentalists, authorities are preparing to limit their choices in where and how to live. Unmanaged, the rabble will opt for too much grass.

Or take schools: Even if my kids could walk to one, a certain surly constituency still wouldn’t like the one I’d pick. No city in America offers more choice than Milwaukee. The poor can take their state aid with them, so they can opt for Catholic schools just as well as I can, or they can pick Lutheran or Muslim or secular private schools or a slew of charters. The local public system offers everything from phonics drills to Montessori vibes: It’s a parent’s choice.

All this vexes quite a few critics. Half the legislative delegation would rather see the private-school options shut off. Critics darkly insinuate that parents choose wantonly. School board candidates openly pine for the day when everyone went to the same schools. All this freedom makes a considerable number of people reach for a leash.

Wrong instinct. Europe has sought freedom within polite parameters for half a century now, an instinct that’s given it mediocre prosperity and a scandalous demand for antidepressants. In America, tell people their options are A or B and they’re liable to invent an option D, moving to Houston and buying a 15 mpg pickup truck to commute in.

Or a cheap used car, like I did. A new opportunity has changed my wife’s afternoon schedule, meaning she can’t pick up the kids and we can no longer stay a one-car family. For seven years, I’ve been carefree and car-free, as transit advocates put it. That is, I’ve been free to travel anywhere conveniently, provided it was along Route 15.

No more, certainly not with kids. I needed to buy what essayist Walter Hanasz called an “engine of liberty” — that is, a car.

This itself would be viewed in some quarters as reprehensible — backers tout the way walking to school cuts down on driving. But the liberations are many. Mrs. McIlheran is free to pursue a new opportunity, our family’s free to send the kids to the school we think best, even while other people’s liberty upended the old paradigm for supplying that education.

The liberties interlock, in ways that can’t be predicted because individuals’ disparate needs aren’t easily foreseen. If we were made to settle for the neighborhood options, for the sake of social cohesion or reducing exhaust or whatever, then that may further the official goal but at the cost of our being less able to adapt to the consequences of others’ freedom, less able to make the necessary trade-offs.

Leashed, liberty becomes a farce. Better to accept its untamed consequences, even if that means the kids take a ride in the afternoon.

Mr. McIlheran is a columnist for the Milwaukee Journal Sentinel.