the case is also fataly flawed beacuse the speed camera on the ruislip bit of the A40 is set at 70 mph
the greenford/northolt one is the 50 mph one

just in case you want to know, between the greenford and harrow/northolt junctions on the a40 there are 2 camera's at the same spot on either side for the 50 mph one, where the footbridge is
the other one is on the way out towards the uxbridge turning (or the way into town on the uxbridge turning because there is onlyone which they sometimes turn around)
they are both normal gatso's so you can't tell who would have been driving

the coppers normally sit on theperivale overpass to catch you speeding just past the hoover building on the way ut of town normally