[Clemenza]

The higher the density, to say nothing of natural contours (ie river valleys), the better the location for rail. After spending two years in Seattle, I can honestly say that rail would work there, as the metro area lies in a narrow valley with natural barriers that prevent further sprawl (the Sound, the Cascades, and the Olympics).

I don't see rail working in Houston, let alone Oklahoma City.

[Alberta's Child]

I think of "rail" as two different things: rail transit and inter-city rail.

Rail transit is seriously flawed in one key respect: its operational costs are prohibitively high when measured in terms of dollars per passenger-miles traveled.

I do a lot of work in transportation planning and design in my profession -- and one of the things that has become obvious to people in my profession over the years is that it's a hell of a lot cheaper to implement bus service on a limited-access alignment (a busway, or along an arterial road with a bus lane and traffic signal pre-emption to optimize the flow of buses) than to run passenger trains.

One of the well-kept secrets in my work is that buses are TOO flexible for long-term planning purposes. A transit agency that implements a new bus service tomorrow may decide to curtail it, re-route it, or shut it down completely in the future. This makes it impossible to effectively manage any kind of residential and office development along the transit lines served by buses. If a rail system is built, on the other hand, it's a lot easier to plan for future development because it's unlikely that the service would ever be substantially reduced in the future (and almost impossible for the service to be re-routed).