With rail - particularly these days when it&#x27;s practical to work on trains - it&#x27;s not really the speed, it&#x27;s the capacity. And Hyperloop&#x27;s capacity advantage seems to come solely from the assumption that their cars will be allowed to run as close as buses or trams or lorries.<p>We allow lorries to run at 56mph less than a meter nose-to-tail, with a human at the controls. Yet we require signalling blocks that put miles of clear air between two successive trains even when automatically operated. We could make rail vastly more economic overnight if we simply allowed it to operate at the same safety levels that we accept for road traffic.