It’s a particularly hard problem in Texas. We get torrential rains and the landscape is relatively flat. Couple that with shallow soil over lots of limestone and it means flooding is really common. We also have roads that have a “low water crossing,” where a road crosses a creekbed that is normally dry but which will flood. There are often water depth signs there (basically a vertical ruler with feet marks so you can see where the water is up to). We lose people to this scenario (driving into flood waters) every year. It’s particularly problematic when it’s dark and you miss a warning sign. Before you know it, you’re in deep water and the flow can sweep the whole car downstream until it gets pinned against a tree, possibly with water forcing its way into the car.

If they have a laser measurement of the road from before, couldn't they see that the level of water vs the expected road surface?

If they've mapped the surface of the water relative to themselves... couldn't they slowly wade in and just calculate the depth based on that 3d model without extra sensors.

Assumes there's no abrupt cliff to fall off... but short of the ability to make a 3d map underwater that seems inevitable.

This is also why they recommend not to use polarized while cycling, it can obscure slicks or water in certain sections. I still use mine but I know it's not as ideal as photo chromatic lenses.

Pretty sure the right answer mainly involves the car knowing about the weather and other emergency events.

Doesn't Land Rover historically have like a wading sensor?

By a water sensor do you mean a sensor to detect the water level relative to the chassis? It seems like a very inexpensive downward-facing ultrasound sensor could work.

> Humans make that mistake frequently.

They have been known to make that mistake. To use the word "frequently" demonstrates a misunderstanding between number of incidents and total miles driven. It also ignores that humans often drink and most of these types of accidents happen after 2am and most often in the state of Florida.

> equipped with a water sensor

Car washes will be fun.

> DARPA Grand Challenge

The problems the grand challenge ignores are more important than the ones it solved.

Do they make this mistake frequently? How frequently? I've seen people overestimate things, but I don't think this is as hard as one might think

My commaai can do this. I'm pretty sure tesla can as well

Any human can distinguish wet pavement from a flooded street. Some voluntarily drive into the flooded street.

And that is the difference. In a Waymo you are a prisoner, in your own car you can turn around.

> frequently

I've never made that mistake; I'm not aware of anyone I know doing it. I very rarely see it myself, except on news footage. Of course it happens some time somewhere but that says nothing about frequency.

> That's a tough problem

Not really. Don't drive where you don't know it's safe. Definitely don't drive into moving water - puddles only, and only if not too deep: I can usually figure it out based on the rest of the road - unless it's a sinkhole, the geometry is somewhat consistent - and especially by looking at objects in the water such as other cars driving through it. Sorry your friend isn't competent to figure it out.

People here are always quick to defend the autonomous cars, like a close friend. How often will we fall in love with a technology or company? It always distorts the truth.