Speed camera trigger speeds

[wyze]

I went past a GATSO the other day and it didn't go off. I was overtaking and when I looked at my speed I was doing about 70 mph. It was only a 60 mph limit, but this moron was driving slowly and then speeding up as I went to overtake him.

I spotted the camera too late and was on top of it before I realised. But the good news is it didnt flash me. I just hope they always use the flash cos otherwise Ive been caught.

Does anyone know what the trigger speeds are for GATSO cameras, does it depend on the area or road or is there national guidelines?

 

[HDi fun]

If it didn't flash then you're totally clear. Are you certain it was a Gatso? Not a Truvelo, for example?

It's possible the camera wasn't loaded in the enclosure anyway. Most are empty most of the time. Which means it wouldn't have flashed even if you were doing 120mph. (Not likely in a Polo though).

(You must've given your 1.1 Polo a bit of stick to be overtaking on single carriageways , well done )

Sometimes the authorities leave radar and flash units in the housings even if the camera/film unit itself is not present. This is a 'dummy' camera. The radar units in these are not calibrated to evidential standards. Nuisance value really. Just wind people up.

The other possibility is that the radar unit couldn't differentiate your speed from the vehicle you were passing at the time. This is quite common - radar is pretty indiscriminate so if there's any doubt the camera itself aborts the check/measure/photograph process.

Later devices based upon IR laser technology are much more accurate. IR speed measurement has never been used in a true Gatso camera.

There's lots more information here:- http://www.speed-trap.co.uk/Home/Menu1.htm

 

[wyze]

I had a hill to help me and saw an opportunity, the git just accelerated and made it really hard for me which is why I needed to crank it up to 70. I dont think the car had much more to give to be honest.

Thanks for the info. Someone else said that my speedo at 70 was probably only about 65 in real speed. Is that right?

 

[HDi fun]

Your speedo can legally over-read by up to ten percent. Most do over-read. None should under-read.

So your indicated 70 might well have only been 63mph. Which is well within ACPO guidelines (10% + 2mph) means 68mph before they're remotely interested.

Technically the limit is the limit so in theory you COULD be done for 60.1mph. In reality this never happens as the entire camera system (film loading, unloading, postal system etc) could never cope with it. Never mind the courts if we all disputed the matter!! it would grind to a halt in days.

On a de-restricted single carriageway (60mph cars, bikes and light vans) the cameras will in all likelyhood be set to ignore everything until 71-72mph is breached. This way the authorities are not seen to be acting in a petty fashion. Don't expect the same leniency from a traffic officer wielding a Lidar device, however.

The MET police tried a no tolerance policy on the M4 Langley to Brentford section back in 2004. So EVERYONE, even if only doing 70.1mph, got a ticket.

What happened? The average speed went up. Why not, if you're going to get clobbered for 70.1 you might as well get clobbered for 89.9

 

[old-git]

My understanding is that boxes will flash whether there is a camera installed at the time or not. The flashes act as a reminder to other drivers as cameras are speed reduction devices not money making ventures. However, if you wish to contribute to the local authroities coffers it is your choice

 

[turbonutter69]

My understanding is that boxes will flash whether there is a camera installed at the time or not. The flashes act as a reminder to other drivers as cameras are speed reduction devices not money making ventures. However, if you wish to contribute to the local authroities coffers it is your choice

I'm not sure about that mate. Round here someimes they take the lenses out and I do know that they don't flash when there is no lense there.

 

[HDi fun]

My understanding is that boxes will flash whether there is a camera installed at the time or not. The flashes act as a reminder to other drivers as cameras are speed reduction devices not money making ventures. However, if you wish to contribute to the local authroities coffers it is your choice

As for reminders to drivers I am opposed to the message that speed cameras present. It's not as if speed is the only issue.

The message this type of 'modus operandi' puts across is one that says you can drive hideously badly, just do it within the posted speed limit.

We've discussed this several times, and it's not news.

What does worry me, however, is that people still get clobbered in 70mph dual carriageways when there's usually enough time and space to reduce speed. Where are those drivers looking?

 

[WLBjork]

There are also those cameras that use an infra-red flash. IR is outside the human vision range, so don't assume you are clear just because you didn't see the flash.

However:

1)You were overtaking, so may not have been in the camera's "field of view".

2)Speedos tend to read about +10%, so you were probably only doing 63mph, which is under the threshold for prosecution.


Oh, and HDi, the probable answer is "tailgating".

 

[HDi fun]

IR flash is used by Truevelo - these photograph the front of the car, thus enabling easier identification of the driver. Truevelo is activated by a pair of inductive loops mounted in the road surface.

As such, the are immune to radar detection devices. A good GPS based warning system is adequate. The other option, of course, is to drive within the speed limit.