Waymo halts service during S.F. blackout after causing traffic jams
25 comments
·December 21, 2025terribleperson
JohnTHaller
I saw this recently when the lights were out at an intersection in Manhattan. People kept on driving and almost hitting pedestrians and cars. I called 911 and then directed traffic for 15 minutes until DoT came out and put up a temporary stop sign.
rwoll
Prior to reading the article, I assumed Waymos were stuck due to an Internet connectivity issue. However, while the root cause is not explicitly stated, it sounds like the Waymos are “confused” by traffic lights being out.
jollymonATX
Would have hoped they trained for this but at least now they likely will be.
ajmurmann
That's what I thought. Then I walked buy Waymos stuck in the middle of the block with nobody in front of them.
VonTum
I miss the time when "confused" for a computer program was meant in a humorous way.
JumpCrisscross
> miss the time when "confused" for a computer program was meant in a humorous way
Not sure what about this isn’t funny. Nobody died. And the notion that traffic lights going down would not have otherwise caused congestion seems silly.
victorbojica
Not directly. But what about the emergency services not being able to reach their destinations? It stops being funny really fast
platevoltage
That sounds plausible. Humans for the most part can usually navigate that situation to a point. It wouldn't surprise me if Waymo cars weren't even trained for this scenario.
Zambyte
We should put self driving cars on tracks so they are always out of the way and have easily predictable behavior. Maybe we can even link the cars together for efficiency or something like that.
quantified
Slot cars at the grown-up level.
Adaptive
I couldn't find anything other than their first responders page but IMO any robo taxi operating in a metropolitan area should be publishing their disaster response & recovery plans publicly.
raldi
I'm surprised that either:
1. Nobody at Waymo thought of this,
2. Somebody did think of it but it wasn't considered important enough to prioritize, or
3. They tried to prep the cars for this and yet they nonetheless failed so badly
add-sub-mul-div
Everyone should have understood that driving requires improvisation in the face of uncommon but inevitable bespoke challenges that this generation of AI is not suited for. Either because it's common sense or because so many people have been shouting it for so long.
slavik81
What improvisation is required? A traffic light being out is a standard problem with a standard solution. It's just a four-way stop.
srdjanr
I'd say driving only requires not to handle uncommon situation dangerously. And stopping when you can't handle something fits my criteria.
Also I'm not sure it's entirely AI's fault. What do you do when you realistically have to break some rules? Like here, I assume you'd have to cut someone off if you don't want to wait forever. Who's gonna build a car that breaks rules sometimes, and what regulator will approve it?
raldi
But a citywide blackout isn’t that uncommon.
lelanthran
> But a citywide blackout isn’t that uncommon.
I think too many people talk past each other when they use the word common, especially when talking about car trips.
A blackout (doesn't have to be citywide) may not be periodic but it's certainly frequent with a frequency above 1 per year.
Many people say "common" meaning "frequent", and many people say "common" meaning "periodic".
Tade0
It isn't? To me that's the main problem here, as this should be an exceptionally rare occurrence.
onetokeoverthe
[dead]
ChrisArchitect
More discussion:
PG&E outages in S.F. leave 130k without electricity
joshka
I for one welcome our robot slow-verlords.
asdff
It seems waymo's always fall apart when encountering something that wouldn't be in the training set. Such as a christmas parade:
In my experience, humans respond incredibly poorly to traffic lights being out. There's no sense or reason, just people deciding to drive across the intersection when they feel like it's okay.
Presumably Waymo will make sure they can handle this situation in the future, but I'm not sure there's a really satisfactory solution. The way you're supposed to handle an intersection with no lights (treat it as a stop sign intersection) doesn't work very well when no one else is behaving that way.