All the hype around self-driving cars has obscured the reality on the ground. The basic building blocks of Autonomous Driving are already on the market, and a closer look at the costly options rarely found on dealer lots offers a glimpse as to who is actually in the lead. In Part 1 of The War For Autonomous Driving, I compared the latest semi-Autonomous systems from Mercedes-Benz and Tesla, as of July 2016. Despite expectations that the Mercedes Drivepilot system would match or surpass Tesla’s Autopilot, it was not the case. The 2017 E-Class offered no more than advanced driver assistance system (ADAS), while Tesla Autopilot 7 delivered true state-of-the-art Level 2 autonomy. ADAS includes all the building blocks of semi-autonomous driving, systems like automatic emergency braking, radar cruise control, and lane-keeping assistance. Level 2 autonomy, meanwhile, is the government’s definition of a car that can drive itself for limited stretches, with a human monitoring the situation. In other words, you still need to keep your hands on the wheel. In Part 2, I reviewed the E-Class ADAS in isolation, and came away impressed by Mercedes-Benz’s industry-leading hardware, but disappointed by its hard-coded software, whose lane-keeping system was no match for Tesla's, which incorporates Fleet Learning and wireless updates. While Tesla has since released Autopilot 8 (via wireless update), the rest of the industry is releasing 2017 models, like the new E-Class, whose semi-autonomous/ADAS features are likely to remain unchanged throughout their three- to six-year product cycles. So on the one hand, you have Tesla, with its constantly-evolving software, and the rest of the industry, with individual models in various stages of obsolescence until the next new tech leap is unveiled. It makes harder an already logistically difficult job of head-to-head comparisons between systems. This past week, thanks to a test day for journalists, I had the chance to get into a bunch of cars one after the other. It was a great opportunity to get an overview of the current crop of technologies, but required quick and efficient evaluation. I decided to focus on the feature most easily evaluated in a short span of time; a feature that, when it works, however briefly, shines a light on our autonomous future—but when it doesn’t, makes it seem like the old ways are still the best. That feature: lane-keeping assistance systems. If the Mercedes-Benz versus Tesla comparo is any guide, not all LKAS is created equal. Let's see where we stand.

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The Battleground Every year the International Motor Press Association (IMPA) hosts test days at which a wide variety of manufacturers bring their latest vehicles. This year the event was held at the Monticello Motor Club in upstate New York. While my colleague Lawrence Ulrich tested cars like the Dodge Viper GTC and Jaguar F-Type SVR on and off-track, I took the opposite tack. With over seventy cars to choose from—only ten of which the other journalists wanted to drive—my job was easy. Just walk up to anything on the lot with LKAS, and drive away. I drove everything available within the time I had. Alas, Hyundai, Ford, and BMW didn’t have LKAS-equipped vehicles on site, and I didn’t have time to test the Toyota, Nissan or Infiniti products. The Route The Monticello Motor Club sits on Cantrell Road, an undulating, tree-lined, road with few markings. Head west, and in under a mile you hit Route 42. Turn left and you have 2.5 miles of ideal conditions suited to even the most primitive LKAS system, before you reach the Post Office at the intersection of Route 42 and French Clearing Road. Excluding Cantrell road, our round-trip test course covered five miles.

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The Conditions Perfect. The Test To be fair, an LKAS test was really all I could do. No manufacturer but Tesla will claim anything but ADAS, and since one day isn’t enough time to adequately test even a single ADAS suite, LKAS it had to be. But this is 2017 stuff; Tesla Autopilot is out there at Level 2, and its Autosteer behavior is exceptional, so if manufacturers want to limit themselves to ADAS there's no excuse for releasing LKAS functionality that’s half-baked. LKAS is easy to test. When your life depends on it, a feature either works or it doesn’t. As per manufacturer instructions, I kept one hand gently on the steering wheel at all times. I would head south on Route 42, at or below the speed limit, attempt to engage each car’s LKAS system, and try to keep it engaged for as long as possible. If the LKAS required cruise control, I activated that first. If the car made it the 2.5 miles to the Post office in relative safety (note that my safety standards are both low and flexible), I turned around and did the same thing on the way back. If the car’s LKAS couldn’t engage in these perfect conditions, or wouldn’t remain engaged, then I would drive it back myself and rank it for safety against my Level 1 (i.e. non-autonomous) benchmark, my Cannonball-Record Setting 2000 Autobahn Polizei E39 BMW M5. Why? Because I believe an attentive driver in a car with zero automation is safer than the average driver in a car with current-generation ADAS. Scoring That task of LKAS is to help keep a human driver, whose hand is on the wheel but whose attention is wandering, stay in their lane. It doesn't have to be perfect, but it has to work sufficiently that the driver trusts it—and it definitely can't work erratically to the point where it's dangerous to engage. With that in mind, my scoring system is a simple yes-or-no question: Can you use it? Let the battle begin. 2017 HONDA ACCORD

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According to George Hotz, a Honda Civic with a Touring package—almost $8,000 more than the base model—has the best LKAS system on the market other than Tesla Autopilot. Alas, no Civic was available, but a 2017 Honda Accord Hybrid was, and it had LKAS. Hotz said it wasn’t as good. I can’t speak to how it compares to the Civic’s, but I was impressed out of the gate. The Accord made it most of the way to the post office without any drama, but the LKAS display is too small to see whether the LKAS lane markers are active (white) or inactive (hollow). Also, the lack of audible notifications is inexcusable. There is a bizarre logic to the LKAS, which gives me pause. It works even if the Radar Cruise Control is disabled. Who wants to have the car steer while having to control the throttle? Not me. Can You Use This? Yes(ish)—you want to use this with cruise control, or not at all Honda Accord or E39 BMW M5? Winner: Honda Accord 2017 VOLKSWAGEN PASSAT

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The VW system was unable to consistently engage, which was a disappointment, because the LKAS display was sufficiently large that I could understand when it was engaged—which wasn’t often enough to rely on it all. It did have audible warnings, though. Can You Use This? No Volkswagen Passat or E39 BMW M5? Winner: E39 BMW M5 2017 CHRYSLER PACIFICA

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A gorgeous minivan. Amazing. Wonderful. But the LKAS wouldn’t engage most of the time, and when it did, it could barely hold the lane. The large situational display is therefore useless. I loved the Pacifica. Its LKAS? Not so much. Can You Use This? No Chrysler Pacifica or E39 BMW M5? Winner: E39 BMW M5 2017 CD CT6

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Another gorgeous car, but it’s LKAS was inconsistent. Again, a tiny display that was all but useless. I liked the haptic lane-departure warning through the seat bolster, though. Can You Use This? No Cadillac CT6 or E39 BMW M5? Winner: E39 BMW M5 2017 MERCEDES-BENZ E-CLASS

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Testing this LKAS system in the Bay area, I hated it; likewise in and around New York City. But on Monticello’s perfect roads, I saw it in a different light. It was almost as good as the Honda, and made it all 2.5 miles to the post office with only two questionable moments. Its display is better than Honda's, but it has the same problems with lack of audible warnings for engagement and disengagement. The lesson? LKAS performs very differently, even in conditions that would appear similar. What was it about the lane markings in the Bay Area and NYC that upset this Mercedes-Benz? There's a lot more work to be done here. In that vein: Dear Mercedes-Benz, Your R&D team needs to get out onto roads outside of Germany. Get this working on roads with a wider variety of markings, or duplicate Tesla’s Fleet Learning and wireless updates, and you’re onto something. If only everyone lived with roads as good as Monticello’s. If only. Can You Use This? Yes Mercedes-Benz E-Class or E39 BMW M5? Winner: Mercedes-Benz E-Class 2017 VOLVO S90

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I set several driving records in a similarly gorgeous S90 across Europe and the United States this past summer, attempting to maximize Volvo’s PilotAssist along the way. At night and in light rain, it did better than expected—as long as road markings were clear. In other words, Swedish, French, and Spanish highways were ideal. Here, the Volvo was slightly better than the Mercedes-Benz, and tied with the Honda for lane keeping. But the S90 had a tendency to hug the brighter of the two lane markings. Keep those hands on the wheel. Display and warnings are insufficient, but it made it to the post office with only one questionable moment, so it gets a "yes," in perfect conditions. I wonder how it would do in the Bay Area or NYC environs, which is where the E-Class had real problems. Can You Use This? Yes Volvo S90 or E39 BMW M5? Winner: Volvo S90 2017 MAZDA CX-9

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I love Mazdas, especially the Miata, but an impressive ambassador of LKAS, this is not. Despite many attempts, it failed to engage, and the display was insufficient. Drive this one yourself, like all Mazdas are really meant to be driven, and you’ll love it. Can You Use This? No Mazda CX-9 or E39 BMW M5? Winner: E39 BMW M5 2017 LEXUS GS-F

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The system barely engaged and the display was tiny. But it's a terrific car, meant to be driven by a human. Turn off all the aids and enjoy it. Can You Use This? No Lexus GS-F or E39 BMW M5? Winner: Tie 2017 AUDI A6

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A nice display, but the LKAS just isn’t there. Come on, Audi. You’ve got to match Mercedes-Benz and Volvo. It’s late 2016. Can You Use This? No Audi A6 or E39 BMW M5? Winner: E39 BMW M5 2017 JAGUAR F-PACE

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