Detroit still seems like an easier environment than Uber/CMU's Pittsburgh, home of barely-maintained brick roadways with blind corners on 20%+ grades and icy winters.
Thankfully, the PGH left is starting to die off as they install newer traffic light systems with dedicated turning lights/lanes.
There are very few brick roads in Pittsburgh. Most are in older sections of the city where the residents have lobbied against a paved road for one reason or another.
And I would imagine steep hills and icy conditions are exactly what you want to test self-driving cars on to see how they handle it.
Many places still have brick. It's not a majority, but it's not a couple of historic district streets either.