The first of Ford’s autonomous cars will have the freedom to drive themselves, but they won’t have the freedom of the open road. That’s according to Jackie DiMarco, chief engineer for autonomous vehicles at Ford, who says the company’s early self-driving cars will operate inside “geofences,” tying their incredible power of robot navigation to a defined geographic area.

One of the most important facets of true level 4 autonomy — a system in which the user of a self-driving car has no direct control over the vehicle — is accurate mapping. While computer vision technology is integral to many autonomous systems, the more the cars know the roads they’re driving on the better. That’s where geofences come in. DiMarco says Ford’s autonomous vehicles — which the company wants to have in widespread production by 2021 — will operate inside designated areas that have been mapped out in painstaking detail.

“When we talk about level 4 autonomy, it’s fully autonomous within a geofence, so within an area where we have a defined high definition map,” DiMarco told Inverse. “Once you have that map you can understand your environment. You can understand where the lamp posts are, where the cross walks are, what the rules of the road are, speed limit and so on. We look at autonomy as growing within a certain geofence and then expanding on there as the technology comes along, as our learning comes along and as our ability to solve more and more problems comes along.”

And it makes sense: for the vast majority of daily commuters or people using cars to get around in cities, trips don’t stray outside of certain area.

“You could imagine a geofence could be Manhattan, it could be southeast Michigan with the corridors to the airport plus the major Metropolitan areas,” DiMarco says.

If you think this vision sounds different than the fully-autonomous cross-country road trips Elon musk has promised Tesla owners, you’re not wrong. Ford’s game plan for autonomous vehicles isn’t to make a car that’s perfect in every situation or on every road (at least not yet). Instead, Ford’s oft-stated focus is to have a fully-autonomous ridesharing car, one that perhaps doesn’t even have a steering wheel or pedals. The vehicle that DiMarco’s team is developing capitalizes on the company’s new identity as a mobility company, and the possibility that a subscription model will erode personal ownership of vehicles. Ford sees more demand in a basic vehicle that can make short range trips for multiple users, ferrying commuters to and from work and around the cities and metropolises they live in. The difference, DiMarco says, is treating autonomy not as an “interesting feature on a luxury vehicle,” but as “something that just makes financial sense and adds convenience to your life.”

The U.N.’s rough estimate is that by 2020, over 66 percent of the world’s population will live in cities — and that percentage will be even higher in heavily industrialized nations like the U.S., China, and most of Europe. While city dwellers may love the concept of a road trip as much as anyone, their day-to-day travel demands are often consolidated in a relatively small area — perfect for the concept of geofences.

Ten years from now, in 2027, DiMarco says she hopes Ford will be expanding the geofences that its cars can drive in, as well as starting to focus on bringing the same system to other metropolises around the world. And if you really want to go cross country without touching the wheel, you can always just take the train.

Photos via Flickr / Stuck in Customs