So I went and got a picture of it at lunch time. It's snowing here and the road is wet so unfortunately it has quite a bit of water in it. It is also on a dual carriageway which was luckily quite quiet. I was in and out of there pretty quick, also judging the lights so I knew no high speed cars were approaching. Still scary as hell standing there though.
There is a fracture line all the way along the road which is easy to see on the photos and there are multiple 'dents' which will in time likely become bigger holes. At busy times you would rarely go through at high speed as this line is immediately after the white stop line and with traffic build up you just don't get a chance to do more than 30 really.
At non busy times though you could be going through this junction at up to 70mph in theory.
The hole in question gradually deepens and then has a flat rise which explains why the impact felt so hard. The camera is not a good indicator of depth, but I'd say the gap was around 3-4cm. I feel I should not be obliged to measure this exactly however as it is far too dangerous. 3-4cm doesn't sound much but at dual carriageway speeds that's a pretty big impact.
I think ordinarily a car would only only catch the right side of this hole which would not be too bad either, but as a police car turning right to my right was almost in my lane I moved to my left slightly basically driving straight through the deepest part. Thank god I was only driving at around 40, I can only imagine what my front suspension would look like if I hit this at a higher speed.
Here are some pics : https://www.dropbox.com/sh/ew1ev7rcxi62534/XZvTd8TVVg