I don't know. It's all pretty expensive just to be a nod to the cyclist. Maybe it's up there with electric cars; you have to get it visible and make mistakes and get it mostly wrong but it's a heck of a lot better than doing nothing and not raising visibility and awareness.
It -does- seem to be working though. As "Cyclists in the City" says, more bicycles than cars cross bridges in London in the morning peak hours and that's been increasing at incredible rates for the last couple of years. It may not be much safer, but there are a buttload more cyclists out there and the numbers keep going up.