You do not need rails to have street cars, in fact it simply is cheaper and better, let alone more flexible, to rely on automated buses going forward. While initially you now need a drive going forward automation can play a bigger role.<p>When you go rail you immediately restrict yourself to that route. There is little to not flexibility. Let alone rails on the roads in snowy climates just cause additional issues. As for simulating with buses, you can embed in the roadway or even on light poles or similar along the route where you want the bus to go when automated. Hence its &quot;on rails&quot; without physical rails.