Many of my car photos that I have posted on DA are taken from a footbridge that crosses the M4 Motorway in Newport.
For those of you who are curious as to its location etc the easiest way to show it is via Google Maps.
Type in Kier Hardie Crescent, Newport.
You will see a "bump" in the road pointing towards the "Old Rectory".
Zoom in on the M4 between these points and drop the "Google Guy" on to the motorway.
Twiddle the direction thingy and you should pick up the footbridge.
There is a blue gantry close by there, but the police get very shitty if you try and climb on that!
There you have it really.