Take a look at town maps for older small towns along the rivers and rails and roads of the midwest. Might give you some ideas.

Pigeon Forge and Gatlinburg, Tennessee, at the very foot of the Great Smokey Mountains, are built along the main road in and out of the national park there. The way things look, these towns are fifteen miles long and only a couple hundred feet deep, with amusement parks (like Dollywood) and carnival rides filling in any gaps.

Hooray for the Road Town, or Linear City. I know I loved reading about them in Heinlein's various novels. I think it would be relatively practical to start setting up things like this. Hell, the population centers are already following the major highways everywhere you look.

I use the QE2 Highway as an example, running between the Calgary/Edmonton corridor in Alberta. Edmonton is building further and further south along this artery, while Calgary is building north. Smaller communities along the stretch are also branching out along the roadway, and others are being annexed by the bigger population centers. Everyone figures its only a matter of time before the two huge cities meet in the middle.

Though if they stop the sprawl this might cease, but who knows. Its already quite common for people to live in one city and work in the other, and spend hours a day driving between the two. I'm not sure how the sprawl will be affected if they finally go ahead with building the high-speed rail lines between the two cities.

Wow. Actually I'm wondering if this wouldn't make a great replacement or modification for rail lines or highway(s) today... though I would build two separate buildings separated by the railroad, or have the railroad built beside a single building, that way, in case of some kind of calamity on the railroad, the city itself isn't compromised. Likewise, airstrips and connections to highways could be on the same side as the railroad... hmmm...

Oh, and I xposted this over yonder to continue discussion...
http://paradice.net/phpbb/viewtopic.php?f=45&t=3962