I dont think Google had anything to do with it, it was CMU robotics, CMU's Traffic21, City of Pittsburgh, and East Liberty Development joint project. CMU also made the tech for transit signal priority to work on the future BRT corridors, and has been ready to go from PRT and CMU for many years while DOMI drags its feet.

The problem in East Lib is, as you alluded and another commenter mentioned, every road going through that area seems a main road. The roads would need to be significantly redesigned far beyond just changing the signaling to have any real improvement. There's no reason why Negley and Highland have about the same automobile traffic hierarchy, and same for Baum, Center, and Penn. Penn is a state owned road, Negley and Highland are city owned, not sure about the others. PennDOT is notoriously awful at working with localities to make the local situation better. They just care about "level of service" on their own roads, and pretty much nothing else. Maybe, if I give them some benefit, they care a little about deaths, but not enough to challenge the almighty LOS gods.