Michael Simari Car and Driver

From the February 2020 issue of Car and Driver.



If the self-driving car is the promised land, then today's ever proliferating driver-assist features are the desert. Diminished claims and "it's harder than we thought" mea culpas from self-driving's loudest advocates suggest we'll be wandering here for many years to come.

At least the technology is meandering in the right direction, though. Thanks to recent software updates, the most sophisticated systems—Cadillac's Super Cruise and Tesla's Autopilot—are more capable today than they were initially. This report on those systems includes a lesser known third player. For $998, upstart Comma.ai sells an aftermarket dash cam and wiring harness that taps into and overrides the factory-installed assistance systems in many Honda and Toyo­ta models as well as some Chrysler, Kia, and Lexus vehicles, among others. When activated, Comma.ai's Openpilot software assumes control over the steering, brakes, and throttle, and it reduces the frequent reminders to keep your hands on the wheel. As you might imagine, automakers do not endorse this hack.

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Any one of these systems could confidently track the center of a lane for hours with minimal driver input on reasonably straight highways. Although no automaker admits that infotainment is part of its system's machine learning, right after we went hands-free, Hinder's "Get Stoned" started playing through the Cadillac's speakers. We ignored that suggestion and threw the three systems at the toughest highway kinks, interchanges, and two-lane roads surrounding our Ann Arbor home base until either they or we flinched. There was some of each.

Cadillac Super Cruise

Highs: Locked-on-its-lane control, handles the difficult maneuvers with aplomb.

Lows: Works only on mapped limited-access highways, steering control not as confident at night, very little information shown to the driver.

Verdict: A capable and conservative commuting ally.

General Motors is slinging billions of dollars into self-driving development, but that's not obvious based on what it has on the road today. Super Cruise launched as a $5000 option on the 2018 Cadillac CT6. Right now, it's still only available on that ultralow-volume large sedan, which has narrowly avoided discontinuation. The feature is standard on the mid-level $75,490 Premium Luxury trim and above (but you can't get it on the $97,190 CT6-V). In total, there are only about 4000 U.S.-market Super Cruise cars on the road, but Cadillac promises the technology will be in its new CT4 and CT5 sedans by the end of 2020, before spreading elsewhere within the Cadillac and greater GM lineup. Finally.

Michael Simari Car and Driver

In addition to the typical suite of cameras, radar, and a GPS antenna that's accurate to about six feet, Super Cruise relies on detailed lidar-scanned map information that's stored onboard and updated quarterly via downloads. Super Cruise works only on limited-access freeways that have been mapped, a catalog that recently jumped from 130,000 miles of road in the U.S. and Canada to 200,000. One of Super Cruise's neatest tricks is tracking driver engagement via a camera, complete with infrared lighting so it can see at night. When the system is enabled and has determined the driver is paying attention, a green bar illuminates on the steering wheel. Once Super Cruise is engaged, there's no need to touch the wheel.

When you're not using Super Cruise, the Caddy has a lane-keeping feature, but it doesn't attempt to center the CT6 in its lane, so the car simply bounces back and forth between the lines. It's annoying. Having both one of the most sophisticated systems and one of the least capable systems coexisting in the same vehicle feels vaguely Faustian and completely wrong.

During the day, Super Cruise engenders trustworthiness by locking on its lane. We found it wandered a little more at night. There are no fancy maneuvers here, such as Autopilot's automatic lane changes, and the system immediately disengages once you hit an off-ramp. It also repeatedly shut down at a particular spot on our test loop when we were merely next to an exiting lane. But when it's working, Super Cruise is both smooth and capable.

Tesla Autopilot

Highs: Best user interface, most versatile, extremely capable.

Lows: Dramatic steering inputs when it makes an occasional mistake, no more hands-free capability.

Verdict: One of the best, but can it really evolve all the way to self-driving?

In 2016, Elon Musk prominently promised that by the end of 2017, a Tesla would be able to drive autonomously from Los Angeles to Manhattan "without the need for a single touch, including the charging." Here we are in 2020, and our long-term Model 3, with the third-generation hardware suite upon which Musk's claim was based, doesn't seem that much closer to the goal. And that's even with our car's $6000 Full Self-Driving Capability option, which Tesla promises will actually live up to its name at some point in the future. For now, that option does provide a few extra features, such as automatic lane changes around slower traffic, the ability to navigate highway interchanges, and the now infamous Smart Summon capability, where the vehicle will drive itself through parking lots, sometimes in a far-from-perfect manner, to where its owner is standing.

Michael Simari Car and Driver

Michael Simari Car and Driver

When the software launched in 2015, Autopilot had warning messages but no actual requirement for the driver to touch the steering wheel. However, following a couple fatalities, Tesla made it so the system—now standard on every Tesla—requires a slight jerk of the wheel every 30 seconds on the highway (and every 10 on two-lane roads) to ensure the driver is paying attention. That twitch also keeps automatic lane changing enabled. But tugging at the steering wheel is exactly what you don't want to do when trying to track straight in a lane, and too much driver input cancels steering control and aborts the advanced moves.

Autopilot easily has the best user interface, showing the driver the lane lines it's detecting as well as vehicles (scaled to size), pedestrians, and cyclists in the Model 3's immediate vicinity. Fire hydrants, however, are displayed as pylons. But where Autopilot occasionally erodes confidence is in its willingness to make abrupt inputs. For example, unlike with Super Cruise, the driver can enable Autopilot when the vehicle isn't centered in its lane, but this causes the car to swerve abruptly to the middle. It also spooked us with a dramatic weave when two lanes became three. But it was prescient on two-lane roads, even when the outside lane line was completely obscured by snow, and it's able to function in far more scenarios than the other systems. Overall, it remains one of the best.

Comma.ai

Highs: Capable steering, brake, and throttle control.

Lows: A too-large and unadjustable gap from cars ahead, slows substantially for curves, flashes unnecessary warnings.

Verdict: If this is what's possible with a single camera, perhaps the hardware required for self-driving won't be as extensive as expected.

In 2015, backing up a bold claim that the usual players "are spending way too much money" on self-driving development, iOS hacker George Hotz founded Comma.ai and built a system himself. He was 25. A team of just a half-dozen created the software, which they began deploying in 2017. It now works with 62 vehicles, including most of the Honda and Toyota lineups, and Hotz says that'll grow to 100 vehicles in 2020.

Due to a 2016 NHTSA inquiry, one thing not included in the $998 hardware kit is the Openpilot software required to operate the system. That must be installed after purchase. The software is open source, which means users can and do make changes, including enabling functionality in new vehicles. Hotz says these vehicles are scrutinized much more heavily than extensions within an already supported model line. And for safety's sake, the system won't allow unsafe inputs to be carried out, such as a command requesting maximum braking.

Michael Simari Car and Driver

Michael Simari Car and Driver

Comma.ai's control is based almost exclusively on a single windshield-mounted camera. A model-specific wiring harness plugs into the vehicle's stock front camera behind the rearview mirror. That's where it taps into the car's communication network, which is used for everything from the power windows to the wheel-speed sensors. There it inserts new messages to actuate the steering, throttle, and brakes on its command while blocking the factory communication. However, certain safety systems, such as forward-collision alert, remain functional. There are no warning lights to indicate that the vehicle senses anything is amiss. And if you start the car with the Comma.ai unit unplugged, everything reverts back to stock. There is no sophisticated calibration procedure. Just stick the supplied GoPro mount somewhere roughly in the middle of the windshield and pop in the Eon camera display. After doing nothing more than driving for a few minutes, the system announces it's ready.

Given its lack of sensors, we were shocked at the sophisticated control of the system and its ability to center the car in its lane, both on and off the highway. Importantly, Comma.ai collects the data from the 2500 units currently in use in order to learn from errors and make the system smarter. Compared with the others, Openpilot wasn't quite as locked on its lane, and its control on two-lane roads wasn't as solid as Autopilot's, but its performance didn't degrade perceptibly at night as Super Cruise's did. However, the following distance, which isn't adjustable, is roughly double that of Autopilot and Super Cruise in their closest settings, making us feel as though we were endlessly holding up traffic.

Like Super Cruise, the Comma.ai system employs a driver-facing camera to monitor engagement and doesn't require regular steering inputs. Unlike Super Cruise, it lacks infrared lighting to enable nighttime vision. That will be part of the next hardware update, Hotz says.

Obviously, the system is reliant on the donor vehicle's hardware, including the car's steering-torque limitations. So our Honda Passport couldn't keep up with the sharpest corners and would regularly flash warning messages to the driver, even when the system handled the maneuver appropriately. Hotz promises the next release will dial back the too-frequent warning messages.

Hotz says he has had conversations with car companies about selling his tech, but he doesn't see the top-down approach as the way to win. Instead, he envisions Comma.ai as a dealer-installed add-on. But that will be difficult, as both Honda and Toyota are against the installation of the system in their vehicles. Toyota has gone so far as to say it will void the factory warranty. This seems shortsighted, though, as the carmakers could learn a lot from what Comma.ai has accomplished.