I think the need for rails is probably the deal breaker. You'd have to repave 2 lanes of asphalt to add the tracks, so it would be very expensive compared to b

I think the need for rails is probably the deal breaker. You'd have to repave 2 lanes of asphalt to add the tracks, so it would be very expensive compared to buses and might even approach the cost of light rail. The height issue just means it would have to be on roads that are 3 lanes or wider, so taller traffic can move around it. I don't think the height issue is as big of a deal as the tracks. If they could make this bus using regular tires it would make more sense but then it becomes potentially more dangerous to drivers in cars. In theory the bus wouldn't have much need to change lanes but in practice any driver that did so while cars were underneath could cause a terrible accident.