Detroit may have a lot more complex situations than Grand Rapids, and even thought it gets much less snow it does get storms with several inches which is enough to cover all the lane marking and making things very messy with traction control coming on a lot. I would say they need to deploy to as many cities in as diverse conditions as possible, but that's after they master stuff like in this article.

Once they can traverse Chicago or Detroit in the winter safely then they can try Grand Rapids or Buffalo.

For the record in East Lansing we get a lot more snow than Detroit but we're pikers compared to say Holland or Grand Haven.

I drove in Grand Rapids and Chicago today. I'd take bad weather in GR than here at home any time. More snow more often doesn't mean more difficult to drive, more population and smaller streets here make it way riskier. Ice and sliding are easy problems to account for in code, bad manners are not.