GATSO's distinguishing between cars and lorries??

[nws25]

Hey all, a guy at work (we work for a breakdown/recovery firm) has just had the paperwork through from the office saying they've recieved the NIP and he was driving the vehicle at the time.
Now its a standard rear facing GATSO on an A road, 60 mph national speed limit.
The 7.5 tonne lorry he was driving at the time has a vehicle speed limit on that road of 50mph. And he's been caught at 55mph and are nicking for vehicle overspeed. Surely this isnt possible with a normal Gatso, he's bringing in the paperwork tomorrow so ill know the exact wording.
Any ideas??
Thanks for your time.

[puggit]

There has been anecdotal evidence on this forum where mini-gatso's have been deployed on NSL roads and have flashed car drivers at less than 60 - this is probably what has happened to your friend.

ie - they are out to catch lorry drivers too!

[cptsideways]

Yep definately,

The camera on the A303 Chicklade has been clocking trucks for a few months now. I've seen several flashed as they cruised through at the 56mph speed. Yet it does'nt go off at cars at 70mph.

I presume they set radar beam higher up & the speed setting lower.

Bloody dangerous lorries forcing trucks to do 40mph on major A roads if you ask me.

[Tafia]

nws25 said:

Hey all, a guy at work (we work for a breakdown/recovery firm) has just had the paperwork through from the office saying they've recieved the NIP and he was driving the vehicle at the time. Now its a standard rear facing GATSO on an A road, 60 mph national speed limit. The 7.5 tonne lorry he was driving at the time has a vehicle speed limit on that road of 50mph. And he's been caught at 55mph and are nicking for vehicle overspeed. Surely this isnt possible with a normal Gatso, he's bringing in the paperwork tomorrow so ill know the exact wording. Any ideas?? Thanks for your time.

This has been discussed on another forum and it was said by a BiB that the Gatso can be set to two different trip limits and can detect the difference between cars and trucks.

It is not just the doppler shift that is measured,(speed) but also the amount of radar reflected. A flat back truck will send a lot more radar 'bounce' back to the Gatso than a car. So it "knows" the difference.

I took this up with an aircraft radar wizard and he confirmed it. It was also on the Gatso makers site at one stage but I have been unable to find it lately

[Chrisgr31]

I was wondering this yesterday when I was stuck behind a series of trucks trundling along remarkably slowly.

Perhaps this explains why areas with speed cameras have not seen a fall in accidents. I'll explain my reasoning.

We all know that overtaking is about the most dangerous manouerve one can make. Truck drivers are now driving slower as they might get flashed by cameras. Result is that more cars are having to overtake. Hence more accidents?

[nws25]

Thanks for your help folks, much apprieciated.
Thats really gonna ruin his day tomorrow when i tell him, as i told him he might get away with it as it must be a fault

[richard sails]

Tafia said:

nws25 said: Hey all, a guy at work (we work for a breakdown/recovery firm) has just had the paperwork through from the office saying they've recieved the NIP and he was driving the vehicle at the time. Now its a standard rear facing GATSO on an A road, 60 mph national speed limit. The 7.5 tonne lorry he was driving at the time has a vehicle speed limit on that road of 50mph. And he's been caught at 55mph and are nicking for vehicle overspeed. Surely this isnt possible with a normal Gatso, he's bringing in the paperwork tomorrow so ill know the exact wording. Any ideas?? Thanks for your time. This has been discussed on another forum and it was said by a BiB that the Gatso can be set to two different trip limits and can detect the difference between cars and trucks. It is not just the doppler shift that is measured,(speed) but also the amount of radar reflected. A flat back truck will send a lot more radar 'bounce' back to the Gatso than a car. So it "knows" the difference. I took this up with an aircraft radar wizard and he confirmed it. It was also on the Gatso makers site at one stage but I have been unable to find it lately

I do know a bit about radar, it would be easy to impliment a system which monitored received signal strength and implimented a different trigger speed.
It would be appropiate for a human to review the pictures to confirm that it was a HGV and not just a big reflection off a car but we would not know if this had been done...

BUT I don't know if this has been implimented within GATSO's?

[tonyrec]

Seems like a question for Willcrash?

[Deadly Dog]

nws25 said:

The 7.5 tonne lorry he was driving at the time has a vehicle speed limit on that road of 50mph. And he's been caught at 55mph and are nicking for vehicle overspeed. Surely this isnt possible with a normal Gatso, he's bringing in the paperwork tomorrow so ill know the exact wording. Any ideas?? Thanks for your time.

Any high-sided vehicle that is caught by a radar speed camera must have the speed calculation validated by the road-side markings. Many a slow moving truck has been "caught speeding" because of radar bounce error.

Assuming you don't go down the unsigned form/PACE route, then a challenge to the accuracy of the data can be argued under Section 23 of the 1991 RTA. For example, can the prosecution produce documented evidence to prove that the Gatso was set to measure the speed of trucks at the time of the alleged offence?

Good luck.

[Tafia]

richard sails said:

Tafia said: nws25 said: Hey all, a guy at work (we work for a breakdown/recovery firm) has just had the paperwork through from the office saying they've recieved the NIP and he was driving the vehicle at the time. Now its a standard rear facing GATSO on an A road, 60 mph national speed limit. The 7.5 tonne lorry he was driving at the time has a vehicle speed limit on that road of 50mph. And he's been caught at 55mph and are nicking for vehicle overspeed. Surely this isnt possible with a normal Gatso, he's bringing in the paperwork tomorrow so ill know the exact wording. Any ideas?? Thanks for your time. This has been discussed on another forum and it was said by a BiB that the Gatso can be set to two different trip limits and can detect the difference between cars and trucks. It is not just the doppler shift that is measured,(speed) but also the amount of radar reflected. A flat back truck will send a lot more radar 'bounce' back to the Gatso than a car. So it "knows" the difference. I took this up with an aircraft radar wizard and he confirmed it. It was also on the Gatso makers site at one stage but I have been unable to find it lately I do know a bit about radar, it would be easy to impliment a system which monitored received signal strength and implimented a different trigger speed. It would be appropiate for a human to review the pictures to confirm that it was a HGV and not just a big reflection off a car but we would not know if this had been done... BUT I don't know if this has been implimented within GATSO's?

Well chaps, after a bit of hunting, I finally found it for you all. Here is the Gatso makers site.

www.gatso.nl/navigatie.html

It takes a while to load (seconds, not minutes). When it appears, put your cursor over Products.

Then under "Speed" on the left of the page, click on "Radar"

Use the scroll handle (a cute curvy thing) on the right of the display and roll down to Radar 24. Then get out your tissues and read these words:

"The Radar 24 system can be set to distinguish between cars and lorries"

It also says the Gatso can be set to trap in either or both directions as chosen by the operator.

Ho hum

[Richard C]

said:

We all know that overtaking is about the most dangerous manouerve one can make. Truck drivers are now driving slower as they might get flashed by cameras. Result is that more cars are having to overtake. Hence more accidents?

Yeah and with car drivers all overtaking trucks that are doing 56 at 60.0 for fear of being zapped by a LTI that makes the road soooo much safer doesn't it !!!!

Safety cameras my @rse