I passed under a gantry last night on my way home from work and for the first time ever there was a flash above my head.

As I approached the gantry at very slightly over 60mph along with pretty much every other lane (4 lanes) it was displaying 60.

As I passed underneath I could see the next gantry displaying 50 but the gantry flashed - I am unsure as to whether it my lane or not and I am pretty sure all lanes were travelling at approx the same speed.

Darn camera's now I have to wait to see I suppose.

Anyone have any experience of how long they take to inform you that you have been caught on camera?

Or anyone have any experience of successfully appealing - as I do not believe 63mph in a 60 limit to be excessive - and if the gantry changed to a lower figure out of my sight I don't believe that is fair either.

I've often wondered what they do when they switch the limit on those gantries - there must be a grace period from the time that they switch the speed until they start nicking people.

I'd wait and see what comes back - if anything.

Fingers Crossed

Is the 10% thing a myth?

I am thinking it changed from 60 to 50 without me seeing it - so if there is a 10% rule then I potentially doing 8 mph over the variable speed limit.

There is a chance I suppose that it was flashing at someone in one of the other lanes doing 67mph, 4 mph faster than me but over the 10% rule.

There is definitely a tolerance - I habitually go under variable speed cameras at 3-4mph over the limit. There is no hard rule about tolerance - theoretically you can be prosecuted for 61 in a 60, but it will probably never happen. IIRC, the ACPO guideline is 10% + 2, so you'd need to be doing an actual 69 in a 60 (probably over 70mph indicated) to get flashed.

There's also a "grace period" after the limit is reduced on "smart" motorways - something like 30 seconds or a minute - can't remember.

All lanes will have the same limit - there are never different limits on different lanes (although its possible to have different limits on a sliproad)

The time limit for receiving a NIP is 14 days

I will find out before I leave the country then for the US - Yay!!
thanks Nigel

I had one go off at me once, was a 30 mph zone built up area and i was doing 30
I never heard anything from dvla and was also told (unsure if true) that occasionally they go off to calibrate or test or something?????
im sure you will be fine if it said 60 when you saw it and were doing 63 as you said

I'm sure the area is a big factor. Few years ago I recieved a ticket in Basingstoke on a Sunday morning at 8.32 doing 33 in a 30 limited.

Its two flashes for the camera to have recorded an image

Yeah definitely two flashes
But dunno if it was my lane it flashed on

I have heard (on a TV discussion with the highways agency) that there is a one minute grace period when the limit is lowered before the new limit is enforced...

My concern is that I clock a 60 for several gantries and then realise that they've changed to 50 and I'm never sure whether that was the first one or not... 50 and 60 are too difficult to distinguish on the matrix displays.

That is so possible, I may contest a penalty anyway as I was sure it said 60...

3 points and a compulsory visit to Specsavers

During a speeding awareness course i have not long taken, i was told by a traffic cop that there is indeed a grace period of around 60 seconds once the gantriey changes, this is for safety to prevent people stamping on the brakes and allow people a fair chance
If it changed when you went under it, it wasn't you that was being flashed, or you missed the change a gantriey back.

Well if no-one knows this then it's kind of pointless putting it in place, right?

Funny enough, I said that to him