I'm looking at various ideas for creating a view barrier for a track going into a staging area, and one idea I've got is to use a roadway overpass over the track, with the track curving behind the bridge structure after it passes below the bridge.

My question is, what are typical gradients used for road bridges?  A little more info: the bridge will be in an early 60s era layout, the road will be two lane concrete leading out of the business district of a small town, and I'd like the grade to be as steep as realistically possible.

Has anyone any personal experience with the 125' double track truss bridge from Cambell Scale Models? 

Ideally I'd like to know if it looks like a metal bridge when assembled and painted.

I'm looking for a double track truss bridge, and I've had personal experience with the Walthers. I'd prefer another model if possible (and I haven't ruled out scratch building).

Thanks!

I have built a small hill out of ever-smaller pieces of art store foam core board.  The steps are nowhere as near large as the pink foam shown in magazines.  For an N-scale or Z-scale diorama.  The question is, what do I smooth out the sides with to make a slope  ,,,,,  from what is now a bunch of 'steps'.

I used to use something which, when wet, looked much like oatmeal.  I preferred Durham water putty, but now I want something 'right out of the can, or tube'.

My layout is in the steam period, @1930.  2-6-0 Moguls will be employed.  There maybe an occasional ten-wheeler.