That's a bold claim. Citation?

Driving a motor vehicle does endanger peoples' lives, so we (society) decided you don't have the "right" to do it, but you can be granted the privilege to do so pretty easily provided you have the $$ for administrative fees & can pass a test demonstrating basic competency.

Your question is totally reasonable, but I think it's fair to say one has a "right" to bike on public roads (barring interstates) but not a "right" to drive on public roads as this requires a license & is subject to many strict regulations.

I am interested in why sequoia asserts that it's correct (or at least permissible) to prohibit bicycles from interstates but a violation of rights to prohibit them from other roads. The fact that bicycles are not prohibited from all interstates seems somewhat orthogonal...

This is regrettably untrue. There are far fewer deaths from bicyclists, of course, but if you google you'll see that there's about one a year. Although I'm pro-cycling I have to say I particularly dislike that segment of cycling community which seems to have the attitude that they not only have right of way at all times against cars, but also against pedestrians; I have had far more near-misses from careless or rule-breaking cyclists than with cars.

Corollary: When states declare that bicycles on public roads are subject to the same rules and responsibilities as cars (and most/all states do), sanctions on bicycling are not available as penalties.

"bicycles shall be deemed vehicles and every rider of a bicycle upon a highway shall be subject to the provisions of this Chapter applicable to the driver of a vehicle"

source: http://www.ncga.state.nc.us/EnactedLegislation/Statutes/PDF/...

[1] http://daccess-dds-ny.un.org/doc/RESOLUTION/GEN/NR0/043/88/I...

http://www.un.org/en/documents/udhr/index.shtml#a13

http://en.wikipedia.org/wiki/Freedom_of_movement_under_Unite...

In an ideal world bicycles are given equal respect and stature on the roads. In practice, however, riders have a lot more to lose in a collision with a car.

Since you mentioned "an ideal world," I'm going to completely disagree. I think that bicycles and automobiles sharing roads is, at best, a manageable but extremely dangerous situation. Like it or not, bicycles and automobiles behave very differently, and require their surrounding vehicles to behave very differently. In an ideal world, there would be separate thoroughfares for automobiles and bicycles, and neither would be allowed on the other (like we already mostly have for pedestrians)

If you're talking about sidewalks, it's barely separate, as in a city there are conflicting paths between the road and the sidewalk every dozen feet (every driveway or intersection).

I am not disagreeing, genuinely curious about the argument

ADDED: I did a little research and found other examples of privilege vs. right[1].

[1] http://constitution.org/cmt/right-privilege.htm

If that was a sound argument, then one could say that the right to own a firearm is really just a privilege because most states require a license to own a firearm which may be revoked by the state for a variety of reasons. Or similarly that the right to vote is just a privilege because you must register and there are a variety of reasons for the state to revoke it.

Just because a right is regulated does not make it a privilege.

The right to freedom of movement is not really a right if it does not include by all available means.

For example, to say you have the right to walk from the east coast to the west coast but not the right to drive a car (or ride a train/bus/plane - all arguments that have been made post 9/11) means that you de facto do not have the right to travel from the east coast to the west coast because it is impractical for the vast majority of the population to walk it.

I'm sure there are motor vehicle codes that have adopted the language of privilege rather than right if for no other reason than it makes it easier for them to claim that moral authority later on, but that doesn't make it true in the sense of natural law. Government does not grant people privileges because everything the government does comes from the people to begin with.

Try watching the junctions around Holbourn tube station and you will see several in a few minuets.