Well, cars came into being at first as steam driven, but the weight was high and there were no hard roads, so they got along on tracks = rail road. Later smaller gasoline driven machines came along (first Benz) and it advanced because it freed us from costly, maintenance intensive, food intensive and crap/pee intensive horses. Before cars many large city street were 2-3 feet deep in horse shit. As for control, huge latency issues would hinder large amounts of traffic.