I've driven over it quite a few times, would be a doddle to fly under.
Tempting isn't it! I'm sure that many of us have had whymsical thoughts about flying under a bridge from time to time. Or at-least I have.
However, I think I'm with F3G, the proportions in that image look to me very much like an RC model.
Incidentally the line about "had he hit it, there would have been a disaster" strikes me as nonsense. That much pre-stressed concrete versus a tonne of aluminium - the bridge would barely get scratched.
G