Well, since the roads were built for automobile traffic ....

In the US, all 50 states recognize bicycles as "vehicular traffic" and a
percentage of all federal road construction dollars are now supposed to
be used for pedestrian and bicycle access.

http://www.fhwa.dot.gov/environment/bikeped/index.htm
http://www.nhtsa.dot.gov/people/injury/pedbimot/bike/resourceguide/index.html

I'm realistic enough not to "take" the right of way in front of 18
wheeler while wearing an "I have a right to the road" sign, but I
wouldn't make that statement to an accident investigator after a
car-bike crash. G I'm also realistic enough to know that cyclists
disobey laws as often as motorists, and that the right of way is
granted, not taken.

Barry