And that doesn't even cover the complete variability of traction from one yard of pavement to the next in winter, or the legibility of road markers.
There's a lot of challenges, and I'm glad they're finally getting to it.
There's a lot of challenges, and I'm glad they're finally getting to it.
One particularly problematic variable that will undermine weather calculations and traction will be the complications of road de-icer. In high-altitude inland regions, de-icer is not used, with a few exceptions after storms are long gone and the temperature has warmed. These regions should be a piece of cake for autonomous vehicles. Detroit in mid-winter probably resembles this for a few months due to low temps but humidity will destabilize de-icer during early and later winter. And, temp fluctuations resulting from humidity, coupled with high snowfall, necessitates the use of de-icer to prevent the city from getting buried in. In coastal regions like CA, de-icer more predictably melts and cleans the roads. In regions like Chicago, de-icer will hve every effect imaginable, both creating ice and melting it multiple times a day. But if a road is not de-iced the traction will follow a different pattern. I can’t imagine how a self-driving car could determine this. To further complicat things, de-icer can often create ice and be counterintuitive in only shaded parts of the road. De-icer is used so differently, an so often foolishly in different regions.
Michigan also tends to just salt the shit out of roads. Probably enough to impact the chemistry of the Flint River. Not so much way up North where it stays colder. Sand there.
As far as the cars, they just measure the available traction several thousand times a second. Electronic stability control is mandatory for new cars in many jurisdictions: https://en.wikipedia.org/wiki/Electronic_stability_control#R...
It doesn’t sound like you’re describing the Detroit I grew up in, where dozen+ car pileups are a regular occurrence, particularly the big hundred+ ones on 94 out your way. That’s even discounting the wide-area ice storms that knock out power from everything getting coated in three to four inches of pure ice, which I can remember happening at least four or five times when I was younger. The last couple winters have been relatively light. We are due for a whopper.
Seriously, Michigan winter is accelerated natural selection for drivers. You learn quick or you die.
As for traction on ice, if the vehicle is already on the ice, it’s too late to slow down. I wonder how the cars could know when they are coming up to ice. Humans can rarely know, but have some complicated ways of identifying, I think from glossiness? And ice is much more rare than snow/slush but both can be present side by side. Either way, I think they will figure it out. Sand can be awful to clean up in urban areas when too muh is used.