Now that Shapps has backed off, maybe he's realised that as in pretty much every other country; apart from N.Korea ( surprise, surprise ), the cost, administration and monitoring of such a scheme is way beyond any possible potential advantage.
Interesting that piggybacking on the reports, there were claims that a cyclist can 'easily exceed 20mph' . Yup maybe downhill for most of us except the minority of fit roadies who can probably maintain that for a while on reasonably level ground.