The limiting factor is money. Plenty of people are down to drive buses. But if you think about it a bus is just a gimped version of a light rail / subway. It ho

The limiting factor is money. Plenty of people are down to drive buses. But if you think about it a bus is just a gimped version of a light rail / subway. It holds less people, is less comfortable, more expensive to maintain and operate, and being a bus gives it no benefit at all over rail. The only reason buses exist is because we made some terrible design mistakes with cars.