Michael Andersen writes an excellent piece in the Guardian about the economic benefits of modern bike infrastructure. A few nuggets (the graphics are also worth reading the link):
After years of battling "the business community" for every inch of road space, many cycling advocates seem disoriented by the idea they might now be on the same side. But from Denver to Memphis, some of the loudest voices for a move toward Danish-style protected cycling infrastructure are those who sign the paychecks.
When people use bikes for errands, they're the perfect customer: the kind that comes back again and again. They spend as much per month as people who arrive in cars, require far less parking and are easier to lure off the street for an impulse visit.
By extending the geographic range of non-car travel, bike lanes help urban neighborhoods to develop without waiting years for transit services. By calming traffic and creating an alternative to car lanes, protected bike lanes help to build the sort of neighbourhoods that people enjoy walking around.
Emphasis mine. Any city looking to improve its walkability and transit use would be hard-pressed to find a better use of its dollars than by investing in protected bike lanes and other modern biking infrastructure.
The future of cycling advocacy is one that European supporters have understood for years: it's in understanding that bicycle infrastructure isn't a luxury we splurge on if we think our economies can handle it. The truth is just the opposite: bicycle infrastructure is something we use to create wealth for our cities. It's something that helps us do all the other things our civilization needs.