I remember reading a while back, when Interlocken was being converted from a horse farm to a maze of office buildings and a mall, that plans were underway to build a tunnel under US-36 for bicycles that would lead from the Broomfield network to the Louisville network. Louisville, in particular, has one that runs parallel to 36 for several miles (I think the Coal Creek Trail?) -- you might bike it and see what you think.

Personally I seldom like bike trails, not so much because I don't like the idea of having a multipurpose trail without the noise, pollution and dangers of automobile traffic, but they are seldom direct routes and often curve about in a decorative but inefficient pattern.

Wads has wide shoulders and so does S. Boulder -- that might make an ideal route to Boulder. Once in Boulder, the roads (and trails) are more bike-friendly than any city I've seen. (Except perhaps Austin, TX)

I once did a good amount of biking along South Boulder Road, up and over the hill from Boulder to the old Louisville Compound, back in the days before I got my driver's license and I started to get less exercise.

I much prefer normal bike trails over riding on the edge of the road, even if it does have a wide shoulder.

One of my pet peeves as a driver is bikes (on non-widened roads) who clog up the lanes. One of my pet peeves as a biker is having to contend with cars going at much higher velocities and who have a much greater mass than I do. Even on wide roads, there's always the worry that some fool in an SUV will veer a little out of his lane at 60 mph and be the end of me.

In my ideal world, all major roads would have a bike trail running parallel, separated by a few meters of grass. Wadsworth is a perfect example.

This coming weekend, I'm going to explore heading in the direction of Boulder. Going via Louisville does seem like the most likely way to get there.