Thwarted on the On-ramp: Waymo Driverless Car Doesn’t Feel the Urge to Merge


Tempe, Arizona, that sunny hotbed of autonomous vehicle testing, made headlines earlier this year after a driverless Volvo XC90 operated by Uber Technologies struck and killed a woman crossing a darkened street. The “driverless” vehicle, which had a (distracted) Uber employee behind the wheel, apparently didn’t see the victim. Uber suspended testing after the incident.

Now, Tempe’s making headlines again. A Waymo-operated Chrysler Pacifica found itself the victim of a collision on Friday afternoon, but it’s the behaviour of another Waymo minivan — caught on video by another motorist — that’s generating the most interest today.

First, let’s get that collision out of the way. According to ABC15, a Honda Civic travelling eastbound on Chandler Boulevard in Chandler, Arizona (a few miles southeast of Tempe) swerved hard left to avoid a vehicle that darted out in front of it from a side street. Given the Civic’s speed and the fact its rear end slid out, the sedan carried on over the median and into the westbound lanes, striking the oncoming Waymo vehicle.

Waymo quickly released a video proving that its minivan was merely an innocent bystander in all of this. Given the way the accident unfolded, it’s unlikely a human driver could have done anything to prevent the collision. Sometimes, you’re just out of luck. Moving on…

Five days before that Waymo mishap, a much more benign incident occurred involving a Waymo vehicle. This time, however, it’s a failure that only results in frustration for the occupant(s), and maybe a little lost time.

What we have here is a situation faced regularly by almost all drivers: a difficult merging situation after coming off an on-ramp. If merging onto a freeway is part of your daily commute, jockeying for an opening is hard-wired into your brain. You’re already eyeballing traffic as you come down the ramp, ready to pounce when the moment’s right.

We see the Waymo Pacifica follow all the rules in this video, but the problem lies in the fact that it’s sharing road space with human drivers. Immediately after the solid white line gives way to a broken one, the turn signal comes on. Unfortunately, a minivan-sized gap immediately adjacent to the Waymo vehicle quickly turns complicated. The following vehicle moves right, into the same lane as the Waymo, just as the preceding vehicle brakes. A (very) brief opportunity missed.

Not to worry, however, as a much friendlier gap opens up further ahead. With its blinker still on, the Waymo vehicle passes the Nissan Pathfinder that braked, then a GMC Acadia, positioning itself next to the gap. There’s still a broken white line. For some reason, though, the Waymo vehicle doesn’t take the bait. By the time it reappears from behind the Acadia’s generously sized ass, the lane marker has turned solid again, and the Pacifica’s turn signal is nowhere to be seen. It ends up exiting the freeway via the lane on which it entered.

On board Waymo’s Pacificas are a diverse array of sensors — more diverse than on Uber’s driverless cars. Three LIDAR sensors map shapes and measure distances, while eight vision modules, combined with radar, give the vehicle a good sense of what’s happening around it. At the present time, Waymo’s setup is viewed as the best.

And yet, somehow this vehicle couldn’t merge. You have to wonder if ride-hailing passengers would pay more for this detour. It’s assumed the Waymo vehicle is exercising the utmost caution here, failing to make the lane change due to the presence of a rapidly approaching solid white line (something a human driver would completely ignore). Still, the video illustrates one of the drawbacks of mixing a perfectly mannered vehicle into a fluid, unpredictable environment where people drive like, well, people.

No driverless car is going to “force” a gap. Had there been a human controlling the wheel, however, that Waymo would be on the freeway out of Tempe.

[Image: Waymo]