Surely these would be replacing the double decker buses?
You mean the double deckers that run down narrow back streets and take hundreds of tight turns?
And what about commercial vehicles? Should distribution companies switch from using one artic to 50 Ford Focus vans so as to fit underneath a preposterous straddle bus?
This idea is beyond daft, discussing it as if it could ever be a reality beyond a road specifically designed for this stupid solution is equally daft.
Quite apart from the stupidity of the idea, the ethos behind it of leaving roads clear for ever more private cars is unsustainable and flawed. The correct solution here is to cut 1 or 2 lanes off from car traffic and install a dedicated public transport corridor, be it a segregated busway or light rail line.
Modern China is basically elitist greed overlaid on a fascist state, the growing middle and upper class nuveau riche want to be able to drive their blinged up imported cars so the plebs need to be gotten out of the way, it's all very Thatcherite.