I've fished a lot under bridges over the years and it seems to change from year to year. But the last couple of years, the bite has been better right before dawn and then the first few hours following. The thing is, to get a prime spot, you have to get there in the middle of the night at most places. Others have done better than me at night, mostly they are fishing with jigs along the pilings, but everybody seems to do better right at dawn and the few hours prior after sunrise. A lot of the fish are migrating away from the bridges now and are right next to, or on the spawning flats doing their thing. I'd hit the flats now during the daylight where they are spawning. And I've seen lights be both good and bad. Usually in the shadows of the lights are best for me. They can bring in a lot of trash fish, too, depending on what part of the season. Oct. Nov. and maybe Dec. are my bridge times, though, if I go.