Just to add to this, there have been some ideas floating recently to move the cyclers below the streets [1] or above them [2], but while the former is unworkable, it's hard to say if anything comes out of the latter.

[1] http://www.bbc.co.uk/news/uk-england-london-31298695 [2] http://www.bbc.co.uk/news/uk-england-london-25549789