Speeding - fines - court

Car_54

Arsenal2019 said:

TBagpuss said:

Arsenal2019 said:

Okay,, so with all of the above mathematics going on, if my GPS dash cam said 49MPH,.. I would’ve been doing 49 or less?

No. They are talking about the speedometer in your car, not the GPS.

And even with the speedo, it doesn't mean that you would have been going slower, just that you might be. Legally, a speedo must not show a lower speed that you are actually travelling, but can show a higher speed, within the tolerances FarFetch explained, so manufacturers will calibrate them with that in mind. 

So, if you had looked at your dashboard and your speedo was reading 49 mph, you could be fairly confident that you *weren't* doing more than 49.

The dashcam will be using GPS to work out your speed based on where your car was each time it 'pings' the satellite - so  it's closer to an average speed check, although it's averaging it over very short periods so ought to be fairly accurate except if you were accelerating or decelerating sharply - so if you were doing 55 but slammed the brakes on and went down to 30  when you saw the police camera it might register a speed lower than 55. How accurate it is will depend on factors such as speed, (it's more accurate at higher speeds), signal quality etc.  If it is a built in system it may also 'talk' to your car to increase accuracy.

Update - I went out in my car earlier and drove at 30 mph (digital clock). I then plugged in the dash cam and watched the footage back. It said I was travelling at 28-29 mph .
So I’m guessing this means that my dash cam when it’s said 49MPH would be wrong, and that I was travelling faster

Does anyone know how long it takes for a speed camera to focus onto you before it gets a reading?

I assume that by "didital clock" you mean the speedometer?

As others have explained, speedos (almost always) over- read, so if yours said 30 your real speed would probably be around 27-28. Your satnav seem to confirm this. Nothing there to suggest the satnav would under-read.

Jenni_D

The margin of difference will tend to increase as speed rises. In my car I tend to see the following correlation:

Speedo    GPS
32             30
43             40
54             50
64             60
75             70

Hence I tend to set my cruise control to the left figures on the basis that my actual speed will be pretty much at the posted limits. (I've often sailed past police vehicles - and a queue of vehicles behind it 🤣 - on a motorway with my cruise set at 75 and never been stopped or noticed them showing any concern).

Edit: the previous 2 posts appeared whilst I was typing.

Arsenal2019

Okay. Well I was travelling around a very slight bend and was on a hill.
yesh by digital clock I meant the speedometer. Just that it was showing ‘49’, rather than the actual pin hovering above the mph/km chart- if that makes sense!
and I presume that if Speedo’s overread , showing 33 when in fact you were actually travelling at 30, the speed van would register 30 of course?!
 

Car_54

Arsenal2019 said:

Okay. Well I was travelling around a very slight bend and was on a hill.
yesh by digital clock I meant the speedometer. Just that it was showing ‘49’, rather than the actual pin hovering above the mph/km chart- if that makes sense!
and I presume that if Speedo’s overread , showing 33 when in fact you were actually travelling at 30, the speed van would register 30 of course?!
 

Yes, the speed van will register your actual speed. It has no way of knowing what your speedo or satnav is saying.

Biggus_Dickus

Car_54 said:

Biggus_Dickus said:

Are they parked and left unattended or is there always a Rozzer in attendance?

As explained in the article, yes, they can be left unattended. When attended, the operator is not usually a police officer.

However, not everything in the article is true. E.g. having points on your licence will NOT prevent you being offered a course.

The article says , quote “Those who don't have a clean licence at the time of the office (Sic), or if you have been on the course in the last three years, it is unlikely you will be offered the awareness course as an option.”

However, I was of the belief (perhaps wrongly) that anyone who’d received points for a speeding offence in the previous 3 years would definitely not be eligible for a ‘speed awareness course’;...is that correct?

[Deleted User]

Car_54 said:

Deleted_User said:

49mph on a GPS, assuming 100% accurate for sake of argument, speedo would have been showing 50-55 easily, speedos can over report by 110% of the vehicle speed + 6.25mph e.g. showing 50.25mph when car is really doing 40. Taking 10% as an example, 55mph on speedo - 10% =  49.5mph

Mathematics alert!

1. They can only over-report by 10% plus 6.25, not 110%.

2. At 10%, 55mph on the speedo is 50 mph. The 10% is calculated on the vehicle speed, not the reported speed.

I said they can overreport by 110% of the vehicle speed i.e. 50 can show 55 as per the example
There is no need for a "mathematics alert", I am clearly not saying that the car could show 110% on top of the 50mph 

[Deleted User]

Arsenal2019 said:

TBagpuss said:

Arsenal2019 said:

Okay,, so with all of the above mathematics going on, if my GPS dash cam said 49MPH,.. I would’ve been doing 49 or less?

No. They are talking about the speedometer in your car, not the GPS.

And even with the speedo, it doesn't mean that you would have been going slower, just that you might be. Legally, a speedo must not show a lower speed that you are actually travelling, but can show a higher speed, within the tolerances FarFetch explained, so manufacturers will calibrate them with that in mind. 

So, if you had looked at your dashboard and your speedo was reading 49 mph, you could be fairly confident that you *weren't* doing more than 49.

The dashcam will be using GPS to work out your speed based on where your car was each time it 'pings' the satellite - so  it's closer to an average speed check, although it's averaging it over very short periods so ought to be fairly accurate except if you were accelerating or decelerating sharply - so if you were doing 55 but slammed the brakes on and went down to 30  when you saw the police camera it might register a speed lower than 55. How accurate it is will depend on factors such as speed, (it's more accurate at higher speeds), signal quality etc.  If it is a built in system it may also 'talk' to your car to increase accuracy.

Update - I went out in my car earlier and drove at 30 mph (digital clock). I then plugged in the dash cam and watched the footage back. It said I was travelling at 28-29 mph .
So I’m guessing this means that my dash cam when it’s said 49MPH would be wrong, and that I was travelling faster

Does anyone know how long it takes for a speed camera to focus onto you before it gets a reading?

I have gone past a couple of local digital clocks near me, one shows around 28mph when I am doing 30, the next one, literally less than 100m away, always flashes angrily showing 30 - even when I have deliberately slowed to around 27mph on my speedo.

Another one I know of I cycle past regularly, my bike GPS pretty much always matches the speed shown on the display unit within about 0.5mph e.g. showing 22 if I am doing 21.5-22.5 on the GPS

If your dash cam showed 49, your speedo, could in the worst case scenario of poor calibration, have been showing 60.15mph based on the 110% overread + 6.25mph - I would suspect if you could somehow safely test the digital displays, to get it to show 49 to match the GPS, you would probably be doing around 55 on the speedo

TooManyPoints

However, I was of the belief (perhaps wrongly) that anyone who’d received points for a speeding offence in the previous 3 years would definitely not be eligible for a ‘speed awareness course’;...is that correct?

No that is not correct.

The only criteria for being eligible for a speed awareness course is you must be within the speed threshold (up to (limit +10% +9mph)) and that you must not have done one of the same type for an offence committed anywhere in England & Wales (but see below) within the previous three years, the dates of the offences being used to calculate that period. Courses are run by the National Driver Offending Retraining Scheme (NDORS). Before Covid they ran three types of courses for speeding offenders: a standard one, one for speeding on a motorway and one for speeding in a 20mph limit or zone. Drivers were eligible to participate in one of each type within the three year period.  Since Covid I believe there is only one online course on offer.

The country of Dorset does not participate in the NDORS. So if you participated in an NDORS course for an offence committed elsewhere within the previous three years and then commit an offence in Dorset you should still be offered a (Dorset) course. Similarly if you have participated in a Dorset speed awareness course for an offence committed in the previous three years you will still be eligible for an NDORS course if you offend elsewhere. 

Arsenal2019

Deleted_User said:

Arsenal2019 said:

TBagpuss said:

Arsenal2019 said:

Okay,, so with all of the above mathematics going on, if my GPS dash cam said 49MPH,.. I would’ve been doing 49 or less?

No. They are talking about the speedometer in your car, not the GPS.

And even with the speedo, it doesn't mean that you would have been going slower, just that you might be. Legally, a speedo must not show a lower speed that you are actually travelling, but can show a higher speed, within the tolerances FarFetch explained, so manufacturers will calibrate them with that in mind. 

So, if you had looked at your dashboard and your speedo was reading 49 mph, you could be fairly confident that you *weren't* doing more than 49.

The dashcam will be using GPS to work out your speed based on where your car was each time it 'pings' the satellite - so  it's closer to an average speed check, although it's averaging it over very short periods so ought to be fairly accurate except if you were accelerating or decelerating sharply - so if you were doing 55 but slammed the brakes on and went down to 30  when you saw the police camera it might register a speed lower than 55. How accurate it is will depend on factors such as speed, (it's more accurate at higher speeds), signal quality etc.  If it is a built in system it may also 'talk' to your car to increase accuracy.

Update - I went out in my car earlier and drove at 30 mph (digital clock). I then plugged in the dash cam and watched the footage back. It said I was travelling at 28-29 mph .
So I’m guessing this means that my dash cam when it’s said 49MPH would be wrong, and that I was travelling faster

Does anyone know how long it takes for a speed camera to focus onto you before it gets a reading?

I have gone past a couple of local digital clocks near me, one shows around 28mph when I am doing 30, the next one, literally less than 100m away, always flashes angrily showing 30 - even when I have deliberately slowed to around 27mph on my speedo.

Another one I know of I cycle past regularly, my bike GPS pretty much always matches the speed shown on the display unit within about 0.5mph e.g. showing 22 if I am doing 21.5-22.5 on the GPS

If your dash cam showed 49, your speedo, could in the worst case scenario of poor calibration, have been showing 60.15mph based on the 110% overread + 6.25mph - I would suspect if you could somehow safely test the digital displays, to get it to show 49 to match the GPS, you would probably be doing around 55 on the speedo

Oh S**T! I hope that is not the case!! No doubt very soon I’ll have something in the post notifying me what speed I was doing

Car_54

Arsenal2019 said:

Deleted_User said:

Arsenal2019 said:

TBagpuss said:

Arsenal2019 said:

Okay,, so with all of the above mathematics going on, if my GPS dash cam said 49MPH,.. I would’ve been doing 49 or less?

No. They are talking about the speedometer in your car, not the GPS.

And even with the speedo, it doesn't mean that you would have been going slower, just that you might be. Legally, a speedo must not show a lower speed that you are actually travelling, but can show a higher speed, within the tolerances FarFetch explained, so manufacturers will calibrate them with that in mind. 

So, if you had looked at your dashboard and your speedo was reading 49 mph, you could be fairly confident that you *weren't* doing more than 49.

The dashcam will be using GPS to work out your speed based on where your car was each time it 'pings' the satellite - so  it's closer to an average speed check, although it's averaging it over very short periods so ought to be fairly accurate except if you were accelerating or decelerating sharply - so if you were doing 55 but slammed the brakes on and went down to 30  when you saw the police camera it might register a speed lower than 55. How accurate it is will depend on factors such as speed, (it's more accurate at higher speeds), signal quality etc.  If it is a built in system it may also 'talk' to your car to increase accuracy.

Update - I went out in my car earlier and drove at 30 mph (digital clock). I then plugged in the dash cam and watched the footage back. It said I was travelling at 28-29 mph .
So I’m guessing this means that my dash cam when it’s said 49MPH would be wrong, and that I was travelling faster

Does anyone know how long it takes for a speed camera to focus onto you before it gets a reading?

I have gone past a couple of local digital clocks near me, one shows around 28mph when I am doing 30, the next one, literally less than 100m away, always flashes angrily showing 30 - even when I have deliberately slowed to around 27mph on my speedo.

Another one I know of I cycle past regularly, my bike GPS pretty much always matches the speed shown on the display unit within about 0.5mph e.g. showing 22 if I am doing 21.5-22.5 on the GPS

If your dash cam showed 49, your speedo, could in the worst case scenario of poor calibration, have been showing 60.15mph based on the 110% overread + 6.25mph - I would suspect if you could somehow safely test the digital displays, to get it to show 49 to match the GPS, you would probably be doing around 55 on the speedo

Oh S**T! I hope that is not the case!! No doubt very soon I’ll have something in the post notifying me what speed I was doing

It doesn't matter whether that's the case or not. What counts is the speed you were actually doing, not what the speedo says.