The always interesting Eric Peters reports:
Something strange – and dangerous – happened to me the other day while I was out test-driving a new Toyota Prius.
The car decided it was time to stop. In the middle of the road. For reasons known only to the emperor.
Or the software.
I found myself parked in the middle of the road – with traffic not parked coming up behind me, fast. Other drivers were probably were wondering why that idiot in the Prius had decided to stop in the middle of the road.
But it wasn’t me. I was just the meatsack behind the wheel. The Prius was driving.
Like almost all 2019 model year cars, the Prius has something called automated emergency braking. It’s a saaaaaaaaaaaaaaafety system meant to correct for distracted driving – or just slow-to-react driving.
Sensors embedded in the car’s front and rear bumpers scan the perimeter and if they see something in your path that you don’t – or you haven’t applied the brakes in time to avoid hitting whatever it is – the system will automatically brake for you.
. . .
This instance of non-emergency braking may have occurred because we had an ice storm the previous day. Everything got shellacked with a coating of the stuff.
I scraped the ice off the windshield and side glass before I headed out – as people have been doing for generations – so that I could see. The problem – I suspect – was that the car couldn’t see.
Those sensors embedded in the bodywork were probably still covered by ice, giving the car a case of temporary glaucoma. As a result, the Prius may have thought it saw something in the road – and slammed on its brakes to avoid hitting what wasn’t there.
To prevent this from happening, those sensors must be kept clean. Especially if there’s no way to turn off the saaaaaaaaaaaaaaaafety system tied into those sensors. Which in most cases, there isn’t.
But people haven’t been advised about keeping those sensors clean – at least, not strongly enough. There is info to that effect in the fine print of the owner’s manuals of most cars quipped with this feature, including the Prius.
But even if one is diligent about checking (and cleaning off) the car’s various embedded sensors before one begins driving, what about while one is driving?
Weather happens sometimes.
It was sunny and clear when you left the house – or are on your way home from work – but mid-trip, it begins to snow or sleet . . . and the car’s entire front end (where those sensors are embedded) gets coated by slush/slurry/road spray . . . and the car can no longer see very well or even not at all.
There aren’t warning icons/buzzers in the gauge cluster of any new car equipped with this system (so far as I have been able to determine) to let you know that it’s time to stop and wipe off the bumpers because the car can no longer see – and (like your grandma, who also can’t see very well anymore) might just do something unpredictable.
This is arguably . . . dangerous.
The car braked hard, too.
I can now describe what the dashboard of a Prius tastes like. Needs A1.
There's more at the link, including a video report on the incident.
I'd never heard of this problem before: but then, I also haven't driven a car with predictive emergency braking before. After reading Mr. Peters' report, I'm going to do my best never to get behind the wheel of one, thank you very much!
Who approved this system for production without thinking of so basic a problem, anyway?