M1 Average speed cameras over a change of speed limit
Discussion
Quick question, M1 roadworks with the cameras. I was trundling along at 60 in a 60 limit then realised a while after the change that it had dropped to 50! My own mistake I know but I had a quick look back at the footage. There’s a set of cameras then after just under a mile the first set of 50 signs, after that a bit under a mile again to the next cameras (and the point I spotted the reduced limit!)
Are the cameras covering the limit change likely to be set up to know the average speed including the limit change? Or are they likely to be set at 60 and wait for the next set before reducing to 50?
I guess I’ll have to wait ultimately to see if a ticket arrives but thought I’d ask.
Are the cameras covering the limit change likely to be set up to know the average speed including the limit change? Or are they likely to be set at 60 and wait for the next set before reducing to 50?
I guess I’ll have to wait ultimately to see if a ticket arrives but thought I’d ask.
Please report back if you get a NIP in the next 14 days. all useful info.
By the way, if driving in Lincolnshire, which includes 30 miles or so of the A1, be aware that Lincs Police start prosecuting at 10%+2 mph over the limit. So, for example, if you go through a roadworks camera in a 50 limit at 57, expect a ticket. 60 there would be 4 mph over the safe speed.
By the way, if driving in Lincolnshire, which includes 30 miles or so of the A1, be aware that Lincs Police start prosecuting at 10%+2 mph over the limit. So, for example, if you go through a roadworks camera in a 50 limit at 57, expect a ticket. 60 there would be 4 mph over the safe speed.
BertBert said:
It's not super clear from your description OP, but it looks like you passed two cameras doing 60 after the limit change to 50.
Is that what you are saying?
Bert
I read it as passing the first camera at 60 - In a 60 limitIs that what you are saying?
Bert
Then passing a second camera again at 60 but this time a mile into the 50 limit
As stated, average cameras (I dont think) can cope with a limit change between them- Not saying it can't be done
Sorry, I tried to be clear but failed!

covboy said:
I read it as passing the first camera at 60 - In a 60 limit
Then passing a second camera again at 60 but this time a mile into the 50 limit
As stated, average cameras (I dont think) can cope with a limit change between them- Not saying it can't be done
This is what happened. I thought about it again today, they have to put a limit of the road when you are caught speeding, they couldn't really put 'half 60 & half 50' could they?! Then passing a second camera again at 60 but this time a mile into the 50 limit
As stated, average cameras (I dont think) can cope with a limit change between them- Not saying it can't be done

covboy said:
BertBert said:
It's not super clear from your description OP, but it looks like you passed two cameras doing 60 after the limit change to 50.
Is that what you are saying?
Bert
I read it as passing the first camera at 60 - In a 60 limitIs that what you are saying?
Bert
Then passing a second camera again at 60 but this time a mile into the 50 limit
As stated, average cameras (I dont think) can cope with a limit change between them- Not saying it can't be done
If any of the segment for which the average speed is calculated has a different limit than the one the camera is in, then it would be impossible to differentiate between the two limits so I'd say if you didn't break the higher one you're fine, however if your average speed in a section spanning a 50 and a 60 limit is 75, then you've clearly broken both/either.
markyb_lcy said:
I don't see how it can be done ... at all.
You've given one example already. But it's not hard mathematically. Ignoring the 10%+2 thing for the moment. If the limit changes half way between the cameras, the average speed for the section driven at the speed limits will be 55. So if your average speed is gt 55, you have broken the limit.However, I very much doubt they do that. The policy for the section with the two limits is probably to treat it all as the higher limit.
Bert
BertBert said:
littleredrooster said:
If it's the M1 stretch past Northampton, I'm fairly sure there are multiple cameras in each limit, meaning it would be easy to pair them up to suit each section.
With the question being what happens with the pair that straddle the limit change?BertBert said:
littleredrooster said:
If it's the M1 stretch past Northampton, I'm fairly sure there are multiple cameras in each limit, meaning it would be easy to pair them up to suit each section.
With the question being what happens with the pair that straddle the limit change?Forums | Speed, Plod & the Law | Top of Page | What's New | My Stuff


