[derwiki]

Snowstorms are probably when I’d most want self driving. Back in February driving from Tahoe to SF, they closed the road, not because of conditions, but because too many impatient drivers spun out. I trust Waymo to go the recommended speed and not get impatient.

[radiorental]

Its not always about speed, This winter I was on interstate 93 in a 4WD with winter tyres. I was doing 25-35mph because the roads weren't treated. I still spun out, like many others. The road was an ice rink.

Humans and Control System Models need feedback to operate, and worse still... when any input into the vehicle's controls produce zero results, you will spin out.

My concern with a model in these conditions is that it wouldn't recoginize the fact that other cars were in the ditch and that it should probably slow down

[SR2Z]

When it comes to controlling the wheels to prevent sliding and slipping, the AV control system is unbeatable. The ABS and traction control on a regular car has to cope with whatever control inputs the driver has made; on an AV, the computer models the grip limits of the wheel and plans a trajectory to not exceed them. It's not just for snow but also for changing pavement surfaces and the rain.

The main limitation is still sensors in the snow, but it seems to not be that big of a deal to build sensor packages that are better at seeing in the snow than a human is.

[cucumber3732842]

This is the "works in a textbook" take.

Being able to plot a series of inputs that can more efficiently use available traction than a human doesn't prevent you from blundering your way into a dumb situation where the laws of physics dictate that the only possible outcomes are various flavors of bad ones.

It's not clear how often the software will chose poorly and need to brute force its way out with traction/handling. The fact that they seem to be hedging against this by putting the hardware on particularly performant cars indicates it must happen enough to matter or be rare but bad enough to matter when it does happen.

Waymo will probably also rack up a ton of technically not at fault accidents by being obtuse in traffic since there's when there's snow there's a lot less margin for the "two people trying to pass each other in a hallway" type missteps that behavior tends to create.

[SR2Z]

They put the hardware on performant cars because it would be stupid to choose gas for stop-and-go city driving. Electric cars are fast; a new Honda Civic does 0-60 in 6 seconds!

No, this is not a "works in a textbook" take. The path planner is aware of surface conditions on the road. This is already a big deal because otherwise the AV would not be safe to operate in the rain.

Waymo will not be touched in most of those accidents. I've been driving in snow long enough to know that there are always going to be idiots who drive too fast for conditions and lose control of their car; I'm sure some of them will blame Waymo because it's nearby. I once watched a guy with a TX license plate spin out on a perfectly empty, perfectly straight freeway. Waymo doesn't really need to do anything for human drivers to crash.

[Der_Einzige]

I don’t buy it. Proof you had actual snow rated tires on and still spun out? Otherwise I claim lies are afoot

[rottencupcakes]

I drove up there in the AM Thursday, Feb 18th, during the snowstorm, about an hour before they closed the pass for the rest of the day.

You couldn't see anything. As soon as there wasn't a car 20 yards in front of you, it was a complete whiteout. Ice built up on the wiper as quickly as you could possibly reach out of your window and clear it. Radar would probably be nice, but I don't think it'd be enough to keep driving. The cameras and lidar would be an absolute wreck.

I'm sure we'll get there eventually, but that is really the final frontier for AI driving I think. Waymos aren't even allowed to drive in a snowstorm right now. I suspect that you'll be dealing with Caltrans closing the pass for the rest of your life.

[derwiki]

Fair point, and I know it was bad on Thu. I was traveling back on Monday and, other than avoiding the impatient drivers, conditions were fine.

[pj_mukh]

Snowy/Ice-y driving? Check out all this Canadian work!

http://cadcd.uwaterloo.ca

Disclosure: My grad student advisor.

[walrus01]

In a Canadian context, on a two lane highway, sometimes doing the absolutely safe/totally cautious speed in a moderate snowstorm will result in a very large collection of vehicles behind you, with angry drivers. In particular if the persons collecting behind you are some combination of not very risk averse, commute on the same road every day, and are very confident in themselves because they have dedicated winter purpose studded snow/ice tires on.

Even if you also have good winter tires on, if your level of "caution" could be best measured as normal to high, sometimes it's a judgment call on when you want to pull off to the shoulder for 45 seconds to let a bunch of vehicles behind you pass. I'm not sure this is something any automated driver has been configured for. Or just generally to deal with driving when the road condition could best be described as "two only partially visible ruts in the snow where the tires of previous vehicles have driven, with snow in the centre".

Same thing in somewhere with a climate like upper Michigan or in Maine.

[smilekzs]

Turnouts exist. Unfortunately, head-of-line-blockers are very commonly already overwhelmed by the task of keeping tab of their own vehicle; would be a far stretch to expect them to simultaneously stay aware of traffic situations, spot the turnouts ahead, and then take the turnout.

[drusepth]

The entire city shuts down and loses their mind with just a millimeter or two of snow here. Last time we got 0.25 of an inch there were ~9 accidents within a 2-mile span on the highway in the morning, and we just ended up shutting the highway down for the day.

I love Waymo in other cities, but it'd be especially helpful here during the 1 day every other year that we actually get any snow ... if we ever get snow here again.

[nico]

After skiing in Utah, I wonder why the driving conditions around Tahoe get so bad. In comparison, for most places around Salt Lake/Park City, you never need chains or 4-wheel drive.

[walrus01]

Utah snow at its elevations and climate is more dry and fluffy. Tahoe snow or similar when the temperature is only marginally below freezing is more likely to be wet, slushy. Same thing as snow/ice buildup on the mountain passes over the Cascades in WA when the temperature is hovering just below zero C.

[boc]

It simply snows a lot more in Tahoe from a SWE standpoint. Utah gets similar "inches" of snow, but fractions of the moisture, which if you've ever built a snowman you know the difference between the heavy thick stuff and the powder that doesn't clump. Utah gets the powder, Tahoe gets the sludge (and a ton of it).