I took a regular 747 stagecoach bus straight from Edinburgh Airport that dropped me at the slip road to the south of old road bridge. I crossed the road under the pedestrian passage and climbed the viewpoint arriving there just after sunset. This is also the site where the Unesco plaque is displayed these days. 

I walked around admiring the bridge from several viewpoints in South Queensferry, then walked accross the old road bridge to the north side. Luckily the railway bridge is illuminated at night so it was still worthwhile to do this in the dark. On the north side one can appreciate the cantilever construction better as on the south side it starts further offshore.

After that, my phone battery died from the January winter cold and I took a train that took me back over the bridge to Edinburgh.