Sorry for the delay in replying. The truss span of the bridge, as noted by cn nutbar, is from Central Valley. Including the truss, the bridge is comprised of five spans and, except for the section on the truss span, is laid out on a very gentle "S" curve. In the third picture back (the one with the doubleheader going away from the photographer), the spans consist of one Micro Engineering 30' span, one ME 50' span (both made-up from ME girders and strip styrene for the cross bracing), followed by a kitbashed Atlas through girder (deck removed, girders flipped upside down, with lateral bracing built up from strip styrene) then the CV truss, followed by another kitbashed Atlas through girder. The bridge piers and abutments were cast in Durabond 90, a very hard patching plaster. I made moulds from .060" styrene sheet to suit the site, then glued the piers to the plywood riverbed using yellow carpenters glue. The bridge is removeable in one piece, which was very handy when it came time to add the "water". Every time that I see pictures of any of the bridges on the layout (there are four major ones, all removeable, with only two in areas suitable for photography), I'm reminded of the need to go back and add rust stains and high water marks to the "concrete" work.
As for layout lighting, as mentioned, it's all fluorescent lights, double four foot fixtures using Cool White tubes. I'm not nuts about the colour, but this type gives the most lumens per watt (and is also the cheapest). There are 16 fixtures in the room, which is an odd-shaped 560 sq. ft., and when the second level is built, there'll be another 6 to 8 fixtures added beneath the upper benchwork. The main drawbacks of this type of lighting are the colour and the overall flatness of the light, which renders a lot of the detail unnoticeable and offers little contrast in the way of shadows. As my friend mentioned, the camera compensates for the inadequacies of the lighting.
Thanks to all for the continued warm reception to my layout as showcased by Mister Nutbar's fine photography.
Wayne