Google’s autonomous vehicle company Waymo has won regulatory approval to start testing SAE Level 4 driving without a human backup in California, despite running into teething troubles during similar trials in neighboring Arizona. Waymo gained the go-ahead for trials in Arizona sooner because the state is less populous with many small roads almost deserted and even major highways well suited to testing of autonomous driving with long open stretches and usually excellent visibility.
But when the tests encroached on the suburbs of the state’s one major city, Phoenix, several deficiencies came to light. These mostly concerned maneuvers such as turning left across the face of oncoming traffic, changing lanes under congestion and navigating around clusters of pedestrians. In such cases, Waymo’s fleet of Chrysler Pacifica minivans, earmarked for a future fully autonomous taxi service, were hesitant to the extent maneuvers either took a long time or sometimes never took place at all – because the moment had passed. This did not cause any accidents, although hesitation can sometimes be an indirect contributor to them.
Waymo defended the glitches on grounds of safety, arguing that early autonomous driving robots should be cautious and defensive. That is fine as far as it goes but suggests that Waymo should return to the drawing board before testing SAE Level 4 autonomy in the much more populous state of California, where road conditions similar to the Phoenix area are much more prevalent.
Waymo has decided to go straight for SAE Level 4 autonomy, on the basis that Level 3 autonomy falls on its face, by requiring a human driver to intervene at any moment without it being clear how much attention should be paid to the road. The rules stipulate the human should always be like a co-pilot, fully alert and ready to take over, but that defeats the object of autonomy in the first place -to allow drivers to relax and enjoy the scenery a bit or become more immersed in some infotainment. It could be argued Level 3 is just an interim stage not designed to give drivers a break, but in practice it is impossible for most people to maintain full concentration after handing over the reins.
Ironically this has just been brought home to Waymo itself as the company has had to engage in some Level 3 driving as part of its test program, despite the preference to jump straight to Level 4. As explained by Waymo CEO John Krafcik in a blog, one of its test vehicles recently hit a motorcycle and injured its rider. But according to Krafcik, this occurred as a result of the safety driver changing to the lane on the right to avoid a car abruptly veering into its lane, causing its rear bumper to make contact with the bike.
This may have confirmed Waymo’s desire to avoid Level 3 driving as far as possible but begged the question of how well the vehicle would have coped without the driver given that hesitation was not a safe option in that case. The remedy might have been to accelerate into the right-hand lane and so move ahead of the bike, which the safety driver might have been able to do given greater alertness and awareness of where the motorcyclist was. One would hope the backup driver was already paying full attention, however.
Although there is a consensus that it will take time to address the many exceptional conditions that can arise and give autonomous driving the huge number of test miles it needs before it is rolled out widely, this seems to be undermined by the competitive urge. Waymo has a lead and is determined to maintain it, which is why the Californian regulatory approval is a significant coup.
The vehicles will still though be on a human leash because the regulations require remote monitoring by engineers with the ability to intervene and steer or stop vehicles immediately in the event of a problem. Since the engineers are likely to be alert, it could be said this is actually safer than Level 3 driving, but does mean that human control will only be asserted if it really is necessary. The driverless cars will be allowed to cruise on Californian roads at up to 65 miles per hour (just over 100 Kph).
Waymo may also have an eye on China, where testing of Level 4 autonomy is set to get underway, following publication in August 2018 of national standards for testing self-driving smart autonomous cars on roads. Before that, around a dozen regional governments had set their own guidelines with some significant variations that had hampered national testing. China believes it can gain advantage through a strong emphasis on safety even though it might hold back trials initially.