I had the opportunity to go with a few other photographers to take some evening shots from a motorway pedestrian overpass in Glasgow city centre. We were all new to the "car light trails" genre so set up was a bit hit or miss. A brief visit to the wonders of the web, suggested slow as possible and maybe even some type of ND filter.
These were shot with a 6-stop ND and at ISO and shutter speeds listed.
It was quite light to begin with but I think that the dusk to dark variation lent a bit of interest to the shots.
1: f/16, ISO 64, 13s
2: f/18, ISO 50, 25s
3: f/18, ISO 160, 30s
4: f/18, ISO 160, 30s