This is somewhat interesting. Americabikes.org - apparently a lobbying organization - prepared a "Top 10 Facts on Bicycling and Walking in the United States." Original document (PDF) HERE.
These were the most interesting and meaningful, from my viewpoint:
- 40% of all trips in America are two miles or less, 74% of which are travelled by car.
- Americans spend, on average, 18% of their annual income for transportation. The average annual operating cost of a bicycle is 3.75% ($308) of an average car ($8,220).
(The original document cites the original source of the information. I can't guarantee its accuracy, but my personal observation makes me believe at least those two.)
Several of their "top ten" seem to be oriented toward dedicated paths.
As a proponent of transportation cycling, I'm conflicted on the topic of bikeways, "greenbelts," etc.
While they are wonderful for leisure and recreational cycling, walking, skating, jogging, etc., they are of limited usefulness from a purely transportation standpoint. For a bike to be a car-replacement, the rider needs to be able to safely and efficiently travel to and from the same destinations as motorists. There will never be enough money or real estate to construct dedicated bikeways to all destinations.
Recreational corridors are a great boon to any community. If a bikeway is available that will take me to where I'm going, I'll happily detour a couple blocks to use it. But those corridors are "frosting on the cake" - the cake being a roadway system that I can comfortably use going to all those places, as well as the ones not served by bikeways.