The biggest promise of the much-anticipated era of autonomous driving is that we will soon be free of the chore of driving, able to relax or be productive during all that time we used to “waste” keeping our eyes on the road.

But while I certainly agree that a great deal of traffic-choked driving is a laborious, joyless slog, I’m not excited by this potential future. That’s because there’s a flip side to gaining the freedom to be more productive: the loss of the freedom to be unproductive.

We currently live in a wildly connected world, where almost all of us are available 24/7 via multiple email or chat or social media paths. If someone wants to get ahold of you or ask you to perform some task, they can reach you. Sure, you can try to set rules about when you’re working and when you’re home, but we all know the messy, blurry reality of modern life — everyone is seemingly on call all the time.

Right now, there are two consistent and respected refuges from the demands of productivity: the bathroom and the car. (Airplanes also once guaranteed this freedom until near-ubiquitous in-flight internet enabled us to stay connected 30,000 feet up.)

I think most of us are reasonably aware of what goes on in bathrooms, and, for now, that refuge seems pretty safe, but the car is another story. Generally, one is left alone while driving, because driving is a task that involves life-or-death decisions.

In fact, driving, because of the potential dangers involved, has legal restrictions on how much you can focus on other things at the same time. You can’t sit and look at your smartphone, even though a great many people try, because eventually you’ll end up in a wreck. Driving requires enough of your brain and body to exempt you from really having to do anything else.

There’s so little left in this world acting as a hedge against constant connectivity and engagement that we must defend our last true refuge of freedom.

If you’re driving, you get a pass from so many things: answering phone calls and texts, returning emails, reading things, watching things, deciding things, pretty much everything.

I’m driving. Leave me alone.

But what makes driving so magical is that it doesn’t require all of your brain, and the parts it doesn’t need are free to really enjoy other things. Things like conversations with whomever you’re riding with, listening to music, stories or podcasts and, perhaps most importantly, letting your mind wander into a sort of meditative state where you can really think about ideas or problems.

Right now, companies are racing to be the first to offer a fully autonomous car. Tesla claims its vehicle will be able to self-drive across the country by the end of this year, while Uber, Volvo, GM and Mercedes-Benz have invested millions in the technology. Even nontraditional automotive companies like Uber, with its self-driving research division worth between $5 billion and $10 billion, are getting in on the act.

Although no one really knows when self-driving cars will hit the market, it’s safe to say they are coming.

And when an autonomous vehicle is doing the driving, you and your time will become fair game once again. You will be asked to be more productive, to start work a bit earlier and end it a bit later. Sometimes this may be your choice, but no matter how much you think you hate driving, I guarantee you will find yourself longing for that freedom to be inaccessible again.

The idea that people won’t have to focus on driving once we let the robots take over is almost always treated as an unquestioned positive. But we shouldn’t blindly accept this idea to be true. There’s so little left in this world acting as a hedge against constant connectivity and engagement that we must defend our last true refuge of freedom.

It may be too late, of course. Which just means I’m going to have to start using the bathroom a lot more often.

Jason Torchinsky is the co-author of “Robot, Take the Wheel: The Road to Autonomous Cars and the Lost Art of Driving” (Apollo Publishers), out now.