TFL Cycle Superhighways

Simply the fact it doesn’t need a change in infrastructure, unlike the superhighway

I know what you mean, Ed, but be aware that 'infrastructure' is a much wider term and encompasses things like the number plate recognition technology that the Congestion Charging Zone required. It was a very big infrastructure project not only because of that but also because of the establishment of the Inner Ring Road (around the CCZ), which was basically a cack-handed version of Abercrombie's Inner Ring Road (search for Greater London Plan). That required major changes to all the streets on it.