Speeding on managed motorway-J20-J19 M4

[markswanseajack]

I'm new to this - hope I'm using it in the right way. I've had a Notice of Intended prosecution for doing 53mph in 40mph limit between J20-19 on M4 - new managed motorway section. I do not contest the speed but I believe that the gantry before the camera was showing 60 when I passed it. Why do I recall that? The camera was flashing repeatedly - perhaps 15-20 times! My wife and I both thought limit was 60, the cars around me were going similar speed to me, and as we approached the next gantry, which was showing 40mph, cars were using brakes to slow them down. So, I believe they were working to a 60mph reducing to 40mph as I was.
Anyone else been caught in similar circumstances? Anyone know if it is technically possible for me to be right, or am I 'banged to rights'. Appreciate it if anyone can help.

Edited by markswanseajack on Tuesday 3rd February 13:27

Edited by markswanseajack on Tuesday 3rd February 13:28

[LordGrover]

Dunno. Maybe try pepipoo?

[matchmaker]

So you were doing 53 in a 40?

[karma mechanic]

I'm wondering if your post would make more sense if some of the '40's were changed to '60's. Typos?

[markswanseajack]

Sorry if I've not been clear. I was doing 53. The Motorway is a 'managed motorway' section. In the first part of this the first gantry showed the speed limit as 60 mph. Later, it reduced to 40 mph. My contention is that the gantry immediately preceding the speed camera was showing '60 mph' and it was the following gantry that displayed the reduced speed limit to 40 mph. The Speeding Notice suggests that I missed the reduced limit sign. I am suggesting that the evidence around me, (other drivers doing similar speeds, the camera 'flashing' repeatedly, brake lights showing at the next gantry) suggests that the camera was flashing motorists for exceeding 40 when it should have been monitoring excesses above 60