Originally Posted by
bragi
How do they count bicycle commuters, anyway? I keep seeing confident-sounding statistics about how many people ride to work each day in each city, but have no idea how anyone keeps track of any of it. Sometimes I suspect that city traffic people just believe what bicycle advocates tell them, or that they just make up the numbers themselves.
For one thing, the Census Department surveys households to gather this information. The data is generally considered to be accurate.
http://www.census.gov/hhes/commuting/