How Does The Camera System Work M1 J34 To J33?

[zach]

4 hours ago, Bargepole23 said:

Probably worth passing on your workings/research to National Highways.

 

Otherwise it's just hot air. Plain and simple.

https://assets.highwaysengland.co.uk/CPC_Speed_Band_17092019_v2.pdf

 

Here's some research by some boffins, which has triggered the trial on the M1.

Well, that's enough to put a glass eye to sleep! (only got half way down)

 

It's pretty graphs and dates from 2015 to 2017 up to now. It's a document that probably cost a stupid amount of money to create.

 

Real world scenarios. My car is in 7th gear at 60, goes to 8th just under 70, which lowers the revs/emissions. As pointed out above, people see that 70 sign and the foot goes down. The part when the car goes from 50-70 quickly, kicks out loads of 'nasties' We just lost any gains from the speed drop.

 

I may have read it wrong, HGV > 70mph?

 

The document looks like smoke and mirrors (IMO)

[geared]

Can I get an exemption in my Electric vehicle then?  No NOx emissions whatsoever.

[Bargepole23]

1 hour ago, zach said:

Well, that's enough to put a glass eye to sleep! (only got half way down)

 

It's pretty graphs and dates from 2015 to 2017 up to now. It's a document that probably cost a stupid amount of money to create.

 

Real world scenarios. My car is in 7th gear at 60, goes to 8th just under 70, which lowers the revs/emissions. As pointed out above, people see that 70 sign and the foot goes down. The part when the car goes from 50-70 quickly, kicks out loads of 'nasties' We just lost any gains from the speed drop.

 

I may have read it wrong, HGV > 70mph?

 

The document looks like smoke and mirrors (IMO)

Based on reading half of it, and without much interest it seems?

 

Suggesting that one acceleration from 50 to 70 cancels out the reduction in emissions from 4 miles at 50, which according to the document is typically a 17% reduction, feels like guesswork to be honest, but feel free to show your working.

[Guest busdriver1]

2 hours ago, geared said:

Can I get an exemption in my Electric vehicle then?  No NOx emissions whatsoever.

at the point of use

[rudds1]

13 hours ago, Happ said:

My understanding is that the M1 cameras do not have the suggested buffer that is thought to be on other networks. I believe there was a 3mph cushion when first introduced but I was advised by someone in the RAC that it was reduced to 1mph a long time ago. It’s probably why you see them flash so often as people coast past at the limit.

 

Some car speedos don’t read the true speed - they say 33 but you are doing 30, but this can be changed to read true in coding and most modern cars give the true speed by default now. Obviously there are tolerances on how accurate that is as well - by law a speedo van read 10% faster than you are travelling, but never lower.

 

There is only 1 camera between 34 and 33 in both directions. I have seen the matrix signs switch speeds from say 60mto 50 and always wondered what happens if you are going past the camera and that exact time - you would hope there is a 10 second delay or something before the sense triggers.

 

I suppose you’ll find out whats going on within the next 10 days…

When the speed limit is lowered there is a 59 second grace before camera becomes armed for that speed. 

[Elmambo]

On 06/09/2023 at 13:39, Happ said:

My understanding is that the M1 cameras do not have the suggested buffer that is thought to be on other networks. I believe there was a 3mph cushion when first introduced but I was advised by someone in the RAC that it was reduced to 1mph a long time ago. It’s probably why you see them flash so often as people coast past at the limit.

 

Some car speedos don’t read the true speed - they say 33 but you are doing 30, but this can be changed to read true in coding and most modern cars give the true speed by default now. Obviously there are tolerances on how accurate that is as well - by law a speedo van read 10% faster than you are travelling, but never lower.

 

There is only 1 camera between 34 and 33 in both directions. I have seen the matrix signs switch speeds from say 60mto 50 and always wondered what happens if you are going past the camera and that exact time - you would hope there is a 10 second delay or something before the sense triggers.

 

I suppose you’ll find out whats going on within the next 10 days…

Vehicle speedometers are rarely exactly accurate because of the difference in diameter between a new tyre and a worn tyre, this can be as much as 14,mm. This is why there is a 10% leeway. Don't rely on GPS, speed calculations either, they are only accurate on a level road.

[Guest busdriver1]

On 07/09/2023 at 02:40, rudds1 said:

When the speed limit is lowered there is a 59 second grace before camera becomes armed for that speed. 

If only. Try about 5 seconds. I have the points to prove it. Had I had a dash can I would have challenged it. Went from 60 to 40 and clocked me at 48 with my brake lights on.