Per mile isn't the right metric in cities, where you need to consider throughput. Guided busways exist, but as far as I know nobody's doing platooning yet? Edi

Per mile isn't the right metric in cities, where you need to consider throughput. Guided busways exist, but as far as I know nobody's doing platooning yet? Edinburgh had a guided busway for a few years but eventually built a tram over it because buses couldn't manage the throughput.