One concept worth considering is making track from prestressed concrete. I’m not sure how it would work for the inner city or spans with a lot of curves or branches, but it might be a good candidate for freeway medians.
The groove on top and the corresponding hole in the support structure is for electrical or communication cables, and is meant to be covered by a metal cap. One might be tempted to question whether it is really feasible to cast such a shape. Actually it is really excellent, because by piping steam through a collapsible inner form, the concrete can be caused to set much more quickly. Beams can, in this manner, be removable within hours, allowing multiple castings per day.
The picture above shows the various rubber-mounted running surfaces associated with the previously shown designs. In a situation such as a high-speed longer distance application, not only would the rubber be unneeded, (concrete absorbs sound which, in freeway median applications, wouldn’t be and issue anyway) but most of the steel itself could be dispensed with, as well.
In applications with lots of stations and curves and branches it is easy to imagine a track in terms of a profile that serves all of those needs. For the duration of long, straight runs, however, the metal “fins” used in switching need not be present. Furthermore, larger wheels are probably in order for higher speeds, as suggested in post 56. Therefore the running surfaces normally used for the smaller low speed guide wheels should be removed or recessed, so that the small guide wheels don’t spin. In fact, I’m not sure that any of the steel shown is needed.
Without any buried utilities to prevent more closely spaced support posts, this might be a very cost effective way to handle the commuter market and reduce freeway traffic.
By the way, it occurs to me that most readers, even those with some engineering instincts, would be intimidated by the thought of trying to learn a new program, especially a 3D modeling program. Well the folks at Google are no fools, and they wouldn’t get into the 3D software business if they didn’t have something pretty special.
Here is a chair that I drew in under 3 minutes, following this YouTube tutorial. Try it. It’s fun!