Indeed--the Richard Orr stuff is designed to model "girder rail." Girder rail has a profile like this:
The little lip on one side is designed so the flange of the wheel rides along in that lip, rather than rubbing against the street surface.
Orr rail has a profile like this:
beefier than the real thing, in order to fit the flanges of model railroad equipment.
There are also significant differences between single-point trolley turnouts and dual-point railroad turnouts. A single-point turnout has a single moving point, instead of the two points commonly used on railroads. They are also curved turnouts--I think a lot of Brit turnouts (like Peco 100) feature a curved frog, vs. most American-pattern turnouts which use a straight frog, but the curve on an Orr trolley turnout is something like a 6" radius curve. Considering that 15-18" is considered "very sharp" for railroad traffic in HO, that's quite a jump!
My own experience is kind of different--I am modeling an industrial belt line which was originally powered by overhead and featured a trolley line, but has since been dieselized and the trolley line "bustituted." Because the line was intended to handle railroad freight, the curves are sharp by railroad standards (necessitating slow speeds and careful handling) but not unmanageable. I use Peco "Streamline" turnouts, the sharpest I can find, which work out to something like a #3 turnout when compared to American #4 or #6 turnouts, and my minimum curve radius is 12", about the sharpest curve upon which I can run B-B diesels and 40-50' rolling stock.
For my street trackage--well, I'm not quite done with it, but I use a very different method than Interurban. The track is Atlas Code 100, secured directly to the MDF benchwork. I use 1/8" foamcore sheets as the foundation for my streets and buildings, and use .020" sheet styrene (which I purchase in large rolls from a plastics distributor) for the street surface. I glue this to the foamcore, tuck it under the outer edge of the track, and where glue won't hold it down I add a track nail and cover the nail with squadron putty.
The bit in between the tracks isn't done yet. I paint my rails and tracks a dull brown-black color, and the plan is to use more .020" styrene between the rails, supported by strips of 1/16" stripwood. 1/16" (.0625") plus .020" works out to about the height of Code 83 rail, but I like a little bit sticking out so I can clean it more easily.
Here's an overhead shot of half of my layout so you can see more of what I'm talking about--I use a mix of street running and private right-of-way, as the prototype did. You can see that I haven't put the between-the-rails stuff in yet...