Mercedes' driverless cars need human intervention approximately every 2.08km (1.3 miles), and other makes are totally reliant on frequent switching to manual, according to figures out this month from the Californian Department for Motor Vehicles.
The "disengagement reports" (the times an autonomous car was taken over by the human tester) of the major autonomous vehicle companies that test on the US Golden State's highways and byways are available on California's DMV's website. Driverless tests take place in several other US states, but there is no equivalent law in these places.
Twenty companies were required to produce reports, and 19 did so (class dunce Faraday Future is being followed up by the DMV for not handing in its homework). Seven – including BMW, Volkswagen, Ford, Honda and Tesla – reported that they did no testing on public roads, or at least none in California.
At the top of the list was Waymo, which completed 567,365km (352,544 miles) with 75 cars, and 63 disengagements. That works out at a fairly respectable one disengagement every 9,005km (5,595 miles), which is roughly between a third and half of the average individual's total annual driving distance.
Second was General Motors' Cruise, driving 86 cars a total of 211,910km (131,675 miles). It had 105 disengagements, or one every 2,018km (1,254 miles). However, GM's fleet was involved in 22 collisions last year, and two already this year, which doesn't look fantastic compared to Google/Waymo's three crashes in 2017.
The other manufacturers on the list drove far fewer vehicles and total miles, but many had far more disengagements. Mercedes-Benz, for example, drove three vehicles 1,749km (1,087 miles), but required 842 disengagements, equal to one disengage every 2.07km (1.29 miles) (although only 240 of these were due to the test driver's decision, the rest being automatic). Electronics behemoth Bosch also fared poorly, disengaging its three cars 598 times over 2,340km (1,454 miles), or once per 3.9km (2.43 miles).
John Simpson, of US non-profit Consumer Watchdog, points out that the Californian data is "only a partial picture, because other state regulators aren't protecting their citizens" by requiring similar reports. He added: "Despite the self-serving hype of the manufacturers, robot technology simply isn't ready for our roads without hands-on, behind-the-wheel engagement and supervision by a human driver."
While the above data shows that driverless tech is indeed still a while away from being fully reliable, none of the autonomous vehicle makers that we can think of are claiming to be so, and certainly don't intend to be any time before 2020-ish. We might have reached the "Kitty Hawk" moment for self-driving cars, but still regular interventions by test drivers and the occasional crash can be expected for some time yet. ®