[cma]

As soon as the car descends below what was mapped it should be able to know there is a discrepency.

Satellite monitoring is also available for detecting extensive road work which they could use to invalidate and send out something to remap.

[nomel]

Sure, if you drive around slow enough so you can stop in time. Lets say coefficient of friction is around 0.5. That means you can drive around town at a brisk 12mph, if you need to stop within 10 feet (with 0ms reaction time).

[cma]

People usually drive slow too through flooded sections. They don't have the advantage of any descent of the car diverging from HD maps, or any water level visually below HD map surface serving as an immediate warning.

[nomel]

> drive slow too through flooded section

This first requires knowing you're in a flooded section. That's the gap here, is it not? My point is that you can't use descent AS a "flooded zone" detection because then your speed, by the harsh mistress of psychics, is very limited everywhere you go, flooded or not, because stopping distance has to be kept very short since just a few feet of overshoot, when your flood detection triggers, is the difference between ruined engine or not.

Maybe that's their fix, if a flat mirrored surface is detected, slow way down, because perceiving depth of muddy water before getting in it is hard.

[cma]

I'm assuming there is no issue detecting water over the road, only depth below it that has changed since the HD map was made.

[nomel]

And, we're full circle at this point.

[cma]

They had an issue detecting them here. But my understanding was people were saying beyond seeing the flooded section there is a fundamental problem that they can never solve that if there is new construction under the flooded section lowering the level of the road they can never deal with that. But as long as it is not a sudden dip or sinkhole I think HD mapping can still help with that since they can monitor the cars altitude as it traverses it and detect divergence from what is mapped early.