Based only on Terry's pictures it would seem that the damage to the bridge is far from superficial. To have cracked that I-beam must have taken one heck of a bang. I haven't been able to find out exactly what hit it yet - but it wasn't a car transporter!
The bridge height is clearly marked so there should have been no reason for any sensible driver to even attempt going under it - we're supposed to know how long, wide and high our vehicles are!
The detour route into and out of the estate has always been a nightmare and regularly causes problems as far back as I can remember. I used to live in Crabble Avenue and have clear recollections of lorries getting stuck on Hillside and even losing their load on the tight uphill bends coming from Crabble Avenue onto Hillside Road. I have even had to use that route myself with a truck and it can be quite a buttock-clenching event.