Hi Dave...
I have answered your pm...anything I can do to help.
The roundabout in question is just down the road from me and is a total pain. You do need your eyes everywhere, and it does tend to be an 'every man for himself' job.
There are many crashes there, mainly because of the closeness of the exits.
Peak period exits from the M40 are a nightmare. With all due respect to all posters of the correct ways to use roundabouts, I'm afraid it all goes out of the window here.
It seems that whichever lane you use coming round the roundabout, you will get cut up.
Usual scenario is cars coming from the southern exit to get onto the M40 use the inner lane, then cut across traffic entering from the A40 east or exiting from Tesco's albeit the latter are already on the roundabout.
To be quite frank, I avoid that roundabout like the plague. Living here, I obviously know other routes.
PM me again and I'll see if I can help.

For those of you you with Google Earth Street Views, locate yourself at the A40/M40 junction at Loudwater, near High Wycombe, Bucks, and drive around the roundabout...you will see what myself and Dave are talking about
