In my Scientific American column this month, I wrote about the state of the art in self-driving car technology, as reflected by the Tesla Model 3. We’re nowhere near full, Level 5 self driving, where the driver has no duties except maybe to take a nap. But Tesla already offers features that go well beyond Level 2 (lane-keeping, adaptive cruise control, and exit-ramp-taking, on the highway).
As a now-experienced Model 3 driver, I thought maybe I’d supplement that column with a feature-by-feature report card, to give you a better picture of the current tech.
Self-driving (highway). Like many modern cars, the Model 3 offers adaptive cruise control, which means “speeds up and slows down with traffic.” Unlike regular cruise control, ACC ensures that if the car ahead of you suddenly slows, your car won’t hit it—and if traffic speeds up, your car will keep pace (up to a maximum speed you set). In the Tesla, a trackball on the steering wheel lets you adjust speed (roll vertically) and distance behind the next car (horizontally).
On the highway, the Tesla’s implementation is rock solid, graceful, and secure. If you put on your turn signal to change lanes, it even checks its own blind spot, and, if all is clear, smoothly changes lanes automatically and then turns off the blinker. Grade: A
Self-driving (side roads.) I have a few beefs with the Tesla’s adaptive-cruise implementation (which is, to be fair, marked as “beta”) when you’re not on the highway. First, weirdly, it doesn’t work at low speeds unless there’s a car ahead of you.
Second, in residential areas, it refuses to go more than 5 mph over the posted speed limit (30 mph in a 25 mph zone, for example). That might seem logical, legal, and safe, but trust me: It can make impatient drivers behind you lose their minds.
Finally, a couple of times, I’ve felt the Tesla slamming on its brakes unnecessarily, having seen a big dark shadow on the road or, on a curve, a car in another lane. And, like any ACC feature today, heavy rain, snow, fog, and other circumstances may blind your car’s sensors, resulting in strange behavior. Grade: B–
You can turn on Autosteer (also marked as a “beta” feature) only when you’ve first turned on ACC. Autosteer keeps you in your lane automatically by detecting the painted lane lines cars and other objects around you. It works fantastically in highway driving (which, Tesla says, is its intended use), because the lane lines are generally consistent and clear.
In general, Tesla enforces that idea by requiring you to be driving faster than 18 mph to turn Autosteer on. The exception: You can turn it on even when you’re stopped if there’s a car ahead of you, suggesting that you’re in stop-and-go traffic.
Autosteer can work if there’s only one painted lane line—if there’s a car ahead of you to follow. It also tried to detect stationary objects that jut into your lane, but makes no promises (and, indeed, I had a near miss with one of those). Grade: B
Summon just means asking the car to pull out of its parking place, slowly and carefully, either forward or in reverse. It’s perfect when some idiot has parked too close to you, so that you can’t even get the door open. It can also be useful just to get the car out of the garage, because it means that one button press both opens the garage door and makes the car slowly pull out so you can hop in.
You can adjust various settings: For example, you can require that you keep the Summon button pressed in the app all the time the car is moving. That’s the safest way, since it means that you’re watching the whole time. You can also specify the size of an invisible buffer zone around the car—24 inches, for example; if the car encounters an obstacle inside that zone as it pulls out, it stops to avoid hitting it.
One thing I’ll say about Summon: It is absolutely, positively freaky to watch your gleaming fancy car drive itself empty. Grade: B
Parking. The Tesla Model 3 can also park itself between two parked cars, either parallel or perpendicular. It’s extremely good at it, automatically turning the wheel, braking, shifting into forward or reverse, and so on; you just sit there and marvel, doing nothing. In fact, you try not to panic; in most cases, the car is much faster and more confident than you would be as you try to wedge into a tight spot.
The self-parking works only if you’ve just inched past a spot between two cars. It can’t park if there’s a car only one side (or no sides), which seems odd—but on the other hand, why would you need assistance parking if there’s plenty of room? Grade: A–