Police letter says I excide speed over 30 miles in London what is nearly impossible

TooManyPoints

Whatever issues you may have with the speeding offence you must respond to the request for driver's details within the 28 days allowed. If you fail to do so you will be prosecuted for that offence and the result of a conviction will be a hefty fine, six points and an endorsement code which will see your insurance premiums increase considerably for up to five years.

If you look carefully at the "Notice of Intended Prosecution" it will probably tell you what speed you are alleged to have done. Courses are offered for speeds up to 42mph so if you have been offered a course you must have been doing no more than that speed. If you want to challenge the allegation you must decline the course offer, or the offer of a fixed penalty (£100 and three points) and plead not guilty when you are prosecuted. What speed do you think you were doing?

Car_54

[Deleted User] said:

Deleted_User said:

[Deleted User] said:

Sad how many people say just do the course. It's a stitch up, even if you are innocent it's best not to fight it.

How would anyone fight a ticket based on a fully calibrated speed gun / camera used by a certified professional? Hint: dashcam footage is not sufficient

The calibration certificate could be up to a year out from when it was calibrated. GPS doesn't need calibration, so it's more reliable.

In that year anything could happen. Equipment gets chucked around, banged up.

They need to check that it's set up properly too. Check the ranging by measuring a known distance, but the known distance is usually hearsay.

The operators are often incompetent. There vans rock around as other vehicles pass by, screwing up the measurements.

The instructions for those guns day don't use them through glass. That's why they have a flap at the back of the van instead of a window. But your car has lots of glass at the front. At the range they use them the beam will hit that glass, assuming they even aimed it right.

And that's the vehicle mounted ones. The hand held ones are a joke.

OP, ignore all of the above.

ontheroad1970

[Deleted User] said:

You could try asking them for a photo, to help you determine who was driving. That will then give you an idea of where it was and the likelihood that you are exceeding 30 MPH.

If you were not speeding, the problem is going to be proving it. Police speed traps are not very reliable, but the court will consider that to be strong evidence.

If you have a dashcam with GPS speedometer you could try to introduce that to cast doubt on the police evidence. It's not guaranteed to work though.

Basically it's a stitch up, the system is designed to make it difficult for the innocent. It might be best to just do the course and remember to slam on the brakes next time you see a suspicious van.

That's as sensible as your energy mathematics.  They are very reliable and deemed to be so unless proven otherwise.  A GPS on a dash cam is not completely live - note what a satnav shows.  There is always a lag.  I'm assuming you have saved so much with your EV that you can indemnify anyone that follows your advice.  How very generous you are!

ontheroad1970

[Deleted User] said:

Deleted_User said:

[Deleted User] said:

Sad how many people say just do the course. It's a stitch up, even if you are innocent it's best not to fight it.

How would anyone fight a ticket based on a fully calibrated speed gun / camera used by a certified professional? Hint: dashcam footage is not sufficient

The calibration certificate could be up to a year out from when it was calibrated. GPS doesn't need calibration, so it's more reliable.

In that year anything could happen. Equipment gets chucked around, banged up.

They need to check that it's set up properly too. Check the ranging by measuring a known distance, but the known distance is usually hearsay.

The operators are often incompetent. There vans rock around as other vehicles pass by, screwing up the measurements.

The instructions for those guns day don't use them through glass. That's why they have a flap at the back of the van instead of a window. But your car has lots of glass at the front. At the range they use them the beam will hit that glass, assuming they even aimed it right.

And that's the vehicle mounted ones. The hand held ones are a joke.

Evidence evidence evidence.  Where is your evidence?  Following your advice can cost tens of thousands.   

Herzlos

They already factor an error margin into the camera actions, usually about 10% + a few mph which will more than account for any issues with a rocking van or some glass will have on a lazers time of flight measurement. 

You'd need to actively prove that the camera was wrong, not just throw some doubt on it. That would cost you far more than the ticket is worth and will almost certainly fail, because the camera is certainly accurate enough.

If you were being done for doing 31 in a 30 it'd be a stitch up, but realistically to get an invoice you'll have had to have had a speedo reading well in excess of the speed limit (40+).

forgotmyname

[Deleted User] said:

The calibration certificate could be up to a year out from when it was calibrated. GPS doesn't need calibration, so it's more reliable.

GPS is more reliable? Are you sure?   I must remember that when doing 70mph past Junction 10 whilst in the middle or right hand lanes it tells me
to take the 3rd exit on the roundabout, barely reached where the slip road starts when it gives that message.
Happens with Garmin, TomTom and my cars in built system. 

Always happens in the middle or right hand lane, only sometimes in the left hand lane.  Lots of variables to affect GPS systems.
Something at that junction that affects GPS signals.  Had it happen at variousother places also.

Similar issue on the  A41 when heading North, suddenly shows as being in the middle of a field not on the road, TomTom and Garmin both
affected by that.

If they cannot place you precisely how can it be more reliable than a calibrated device?

Herzlos

I missed the GPS more reliable part, GPS updates periodically rather than instantly, so there's an element of lag but it's usually not important. It can also be messed up by tall buildings or anything that impacts line of sight, as well as being useless in tunnels, it can drop out for 20+ seconds easily. It's fine for average speeds and navigating, but not for an instantaneous speed.

GPS readers are also never calibrated once they leave the factory, because it doesn't generally matter for their purposes.

I've got a GPS on my bicycle and it's usually a couple of seconds behind, which is why people who are really concerned about speed use a sensor on the wheel axle to count wheel rotations.

The speed cameras use a laser and record the distance difference very accurately over a very short period of time.


Of course, if you've got GPS logging data showing you travelling at 20mph and trigger a speed camera at 50mph it will look suspicious. You'd still need more than that to try and prove the speed camera was wrong, given they've at least got certificates to show they are calibrated, and constantly have to defend against such claims.

TooManyPoints

I've just been reading the gumpf about satnavs and other GPS based systems being highly reliable. They're not. They are, at best, an estimate of the speed being travelled at. As mentioned above, an approved device operated in the correct manner (which the police will produce evidence to support) is assumed to be accurate unless the contrary can be shown. Casting doubt on its accuracy by introducing measurements from an unapproved and (frankly) unreliable device will not do. To succeed with this the OP will need expert evidence to show the equipment used by the police is unreliable. The cost of failure is high, with most people leaving court with no change from £1,000 - considerably more if the prosecution enlists expert advice to counter the defence. 

[Deleted User]

So if you don't respond you get a £1000 fine for not responding instead? Could be interesting as a way to avoid points altogether. 

noitsnotme

Deleted_User said:

So if you don't respond you get a £1000 fine for not responding instead? Could be interesting as a way to avoid points altogether. 

“The penalty for failing to provide driver details is  six points and a fine of up to £1,000.”

https://www.jmw.co.uk/services-for-you/motoring-law/failure-to-provide-information