Poster at Kensal Green?

I seem to be getting a lot of planning casework recently.  I was tackled in the street about a possible commercial poster near Kensal Green Tube.  The suggested site is on the Network Rail owned land by the Tube Station; the same land that was used by the engineers when they were strengthening the bridge.  It does noes strike me as a good site for a poster either aesthetically or in road safety terms.