I am frustrated by frequent presentation of what I see as a false dichotomy, i.e. that roadways that do not include special lanes or other facilities conspicuously marked for cyclists are designed for exclusive use by automobiles.
I prefer a highway design philosophy that borrows from the principles of Universal Design, which is a philosophy for the design of facilities and products that makes things easy to use for all users rather than providing separate facilities and affordances (such as a separate sinks and knobs)for people of different abilities. All users are considered important design users, but the ultimate form of the facility may not draw conspicuous attention to its accommodation of less-capable users:
http://www.design.ncsu.edu/cud/about...ormat.html#top