[bus man]

There is something top be said for heavy rail (A real locomotive pulling the passenger cars).

I understand what you're getting at here, but just so you know, "heavy rail" refers to its relative carrying capacity, not the weight of the rolling stock. "Heavy rail" equates to "subway" or "Metro"; e.g. the Red Line in Los Angeles. "Light rail" is somewhat like "trolley"; the Blue Line is a Los Angeles example. The train at issue here is commuter rail.

Full grade separation would virtually eliminate accidents of this type, and enable faster and more reliable operation, for both trains and vehicle traffic, to boot. But it's insanely expensive.

[gunsequalfreedom]

Expensive but being worked on. SoCal just got a billion from the feds. It wont be all for grade separation but as tracks are readied for high speed rail it more and more crossings will be done.