Tortoise or Hare: Who Wins the Self-Driving Race?

The self-driving car may not be the optimal urban mobility solution

Sure, I’d gladly let my car handle crawling through traffic jams. Self-valet-parking would be sweet. A self-homing car that left me “free to drink martinis and watch the sun rise” might be even sweeter. And who wouldn’t mind sleeping right through Nebraska?

Otherwise, I still very much enjoy driving. I’m increasingly paranoid about the electronic trail that tells where I’ve gone and how fast. I’m not ready to pay more for automation. And I still don’t believe the technology will work for those of us who drive the cramped, chaotic streets of cities like Tokyo. To me, the whole self-drive discussion feels overly skewed by the fantasies of the techno-elite who cruise California’s carefully engineered freeways.

Volvo XC90 Uber Autonomous Vehicle

So I’m not staring out the window waiting for a go-anywhere, self-driving Uber/Tesla to roll up to my door. What I do anticipate is something less glamourous: a self-driving electric bus heading for the nearest train station. It’s coming – and soon – because that is a maturing technology addresses a pressing real-world problem: the “Last Mile Paradox.”

In cities like Tokyo, New York and Paris, urban rail is ultra-convenient… if you live/work near a station. In Tokyo – where over 80% of all journeys are by train – “near” in real-estate ads means within 10 minutes’ walk (about one kilometer). The Paris Métro meanwhile boasts that all points in the city proper are within a kilometer of a station. That’s about the outer limit of a station’s market area. For commuters, it’s a pleasant walk on a sunny morning but an ordeal on a cold, rainy night. For subway operators in cities less dense than Paris, though, building a station network that extensive would invite financial disaster. That’s why, for riders and operators alike, the Holy Grail is a better way to go the Last Mile.

Buses have always been workhorses of the Last Mile, covering that distance from stations in 5-10 minutes with reasonable efficiency on main routes at peak periods. But providing frequent, all-day service to within a short walk of everywhere in a one-mile radius is a hugely expensive proposition. With labor typically accounting for 70% of the $120-170 per hour cost of operating a city bus in the U.S., moving each off-peak passenger a mile can cost $20. That’s a huge problem, but it’s one self-drive technology is well-placed to solve. Rather than overcome infinite scenarios, developers need only contend with predictable routes, carefully mapped and groomed. And they are on the case.

Mercedes Benz Future Bus with CityPilot profile

Driverless vehicles are already commonplace in the train systems of cities like Vancouver and Bangkok, but self-drive is now poised to go off the rails and onto the roads. Automated bus tests are springing up in cities like Perth, Lausanne and Helsinki. So far most are boxy little mini-buses, but in Amsterdam Mercedes-Benz is testing a full-size “Future Bus,” slated for commercial production “early next decade.”

Japan, transit-dependent and labor-short, is surprisingly late to the party but showing signs of catching up. DeNa, a mobile game maker, is publicly testing a minibus in Chiba, near Tokyo, while Softbank, a telecom/IT conglomerate, is testing a prototype on a closed circuit.

Meanwhile, the crafty Koreans are pursuing another angle: induction charging. Essentially, that means putting trolley bus wires underground to charge small batteries on each bus. What’s nifty is they don’t need to wire the whole route, just terminals at each end and 5-15% of the road in between to ensure the battery has enough power. Gumi, a city south of Seoul, now has a 15-mile line in operation. Elsewhere, Bombardier’s Flexity tram-cars already use a similar induction system. Once someone mates induction with self-drive, the likely result will be one convenient bus.

Ford Fusion Hybrid autonomous research vehicle front three quarter

No matter who ends up making the buses, Japan’s gigantic passenger rail operators are bound to win big and extend their already crushing advantage over private cars. To scoop up every passenger along the line, rail operators have long followed the “classic Métro model,” building stations every half mile. With underground stations costing upwards of $300 million, that’s always meant many lightly used stops never break even. But the equation changes radically if automated buses can double a station’s effective market radius.

The rail profit picture becomes even rosier if one station acquires the effective market reach of three. Modern EMU trains (electric multiple units with traction on every axle) have amazing torque compared to lumbering diesels. Even so, it takes nearly a mile to reach 79 mph (the U.S. DoT conventional rail speed limit). If trains stop every half mile, their average speed is just 20 mph – only marginally faster than the average Copenhagen bicycle. But if stops are on average three miles apart, two of those miles are at full speed and average speed rises dramatically to 50 mph or above. At that speed, service to distant suburbs becomes highly competitive.

The upshot? We may yet witness a tortoise-and-hare finish in the self-driving race. Right now it looks like those smarty-pants Silicon Valley hares are set to “disrupt” urban transport. But while they’re busy dealing with infinite variables, your creaky old local transit authority may just waddle across the line first.