At a press event today, Tesla announced the release tomorrow of version 7.0 of the Model S software, a big, widely anticipated new build that finally enables the car's self-driving features. Those capabilities were first announced last year and the necessary sensors were added to all Model S cars that have rolled off the assembly line since last September, but Tesla has needed additional time to flesh out the algorithms, which it has been testing this year. The 7.0 release starts in the US on a rolling basis tomorrow, and will proceed to Europe and Asia in the coming weeks pending regulatory approval; the Model X shouldn't be far behind, since it has the same sensors in place.

This isn't a fully autonomous vehicle in the vein of a Google car, though — the primary feature is what Tesla calls Autosteer, which keeps the car in its current lane once you're already on the road and manages speed and distance from the car ahead. On the call, Elon Musk was careful to call out Autosteer as a "beta" feature — drivers are told to keep their hands on the wheel, even when the function is engaged. "We want people to be quite careful" at first, Musk said, while admitting that "some people" may take their hands off the wheel regardless. "We do not advise that," he added. An upcoming version 7.1 will add the ability to send the car off to a garage on its own and come back to pick you up, another feature teased when Musk first announced autopilot capabilities last year.

The fact that Tesla tells drivers to keep their hands on the wheel even when the car is steering for them also helps keep liability squarely out of their court: "If there is an accident, the driver of the car is responsible," Musk said, while also noting that there would eventually be a time that self-driving vehicles are safe and reliable enough to abdicate drivers of that liability entirely.

Other 7.0 features include Auto Lane Change, which will automatically move to the adjacent lane by tapping the turn signal, and Autopark, which continuously scans for available parking around the car. When one is found, the car can park itself. (A number of vehicles across multiple brands and segments now offer something like this, so Tesla's playing catch-up with this bit.) There's also Automatic Emergency Steering and Side Collision Warning, which use the ultrasonic sensors to nudge the car away from danger and alert the driver as necessary.

The system is composed of four sensor types on the car: forward radar, forward-facing camera, 360-degree ultrasonic sensors, and GPS combined with Tesla's own high-resolution navigation maps that track the individual lanes and features of roadways. Those kinds of sensors are found on many modern vehicles equipped with semi-autonomous features like lane keep and dynamic cruise control, but here's where it gets interesting: Telsa is continuously uploading real-world sensor data from 7.0-equipped vehicles to home base — Musk calls it "fleet learning technology" — which means that the autopilot capabilities should theoretically get more reliable over time. The functionality will improve with "each passing week," he says, even without a firmware update, since the car is accessing Tesla's high-res maps.

A map of travel data uploaded from Tesla's autopilot test fleet, showing streets (and even individual parking spots) visited by cars in the Bay Area.

There will be a time when truly fully autonomous cars come, though, Tesla included. Musk said on the call that he thinks his company can have a car ready within three years that lets you sleep all the way from point A to point B — the commuter's dream — but it'll take anywhere from another year to several years to work through the regulatory issues. (That aligns with the predictions of many in the auto industry that regulatory catch-up will be the bottleneck, not the underlying technology.)

These vehicles almost certainly won't be upgraded when that happens, since Musk believes that a "more comprehensive sensor suite" is needed. He doesn't believe in those big LIDAR domes on the tops of Google cars, though. "I'm not a big fan of LIDAR, I don't think it makes sense in this context," he said, noting that it's used on the SpaceX Falcon for spaceflight but can be replaced with more traditional optical sensors on the road. From the appearance of the latest cars Google has putting around Mountain View and Austin, it would seem that they'd disagree — but engineers still have several years before this becomes a commercial decision anyway.

In the meantime, don't take your hands off the wheel of that Model S — at least until Tesla kills the "beta" label.