Handheld Speed Camera Advice Please!

Throbbe

tonys wrote:

Then look at your speedo. Remember your speed in case they send you a NIP since the hand held cameras are notoriously unreliable.

Bit of a popular misconception I'm afraid. Used incorrectly, they can give all sorts of interesting results (readings off stationary objects, doubleing speeds, etc), but with a trained user they're pretty accurate, certainly more so than a car speedo! I spent several years doing speed surveys with one as part of an old job.

As others have said, once the 14 days are up, you can relax.

tonys_3

Throbbe wrote:

Bit of a popular misconception I'm afraid. Used incorrectly, they can give all sorts of interesting results (readings off stationary objects, doubleing speeds, etc), but with a trained user they're pretty accurate, .

it is not a popular misconception. How do we ever know if it was used correctly? How does a trained user know what the invisible laser beam has
focussed on between leaving his gun and returning. Answer- he does not know. How does a trained operator know whether the invisible beam has been deflected by another vehicle or road furniture? Answer-he does not..
All we know that something is wrong is when the anomaly is too great or
in the case of hgv's that can compare the laser gun speed with their own
tachograph/tracking devices. And I'm sorry but "pretty accurate" is
nowhere near accurate enough.

Throbbe

tonys wrote:

it is not a popular misconception. How do we ever know if it was used correctly? How does a trained user know what the invisible laser beam has
focussed on between leaving his gun and returning. Answer- he does not know. How does a trained operator know whether the invisible beam has been deflected by another vehicle or road furniture? Answer-he does not..
All we know that something is wrong is when the anomaly is too great or
in the case of hgv's that can compare the laser gun speed with their own
tachograph/tracking devices. And I'm sorry but "pretty accurate" is
nowhere near accurate enough.

With respect, have you used this type of equipment? User error is always possible, but it almost certainly would have to be deliberate. You can theoretically be prosecuted on the opinion of a traffic officer too. I would hesitate to say all police officers are entirely beyond reproach, but the fault there lies with the user, not the equipment. It's a can of worms that i prefer to leave closed on this forum.

The police equipment has a very tightly focussed beam, so much less prone to the reflection errors my 'civilian' equipment had. To give an idea, they aim at number plates, not just at cars. I'm certainly not saying you can't get errors, but used properly they are as accurate as any other method of enforcement. Where errors do occur, in my experience they're very obvious, not a small variation.

As for 'pretty accurate'. Can you define the sort of error you assume to exist from that? One of my many bad habits is being a bit vague. It's an engineering thing, you'll (almost) never get a definitive statement out of me, but when I say that something is pretty accurate, I don't mean to give the impression that they're OK within a few mph.

On the subject of bad habits, another is not being able to resist taking a thread off topic! Sorry Helen.

zappahey

Throbbe wrote:

As others have said, once the 14 days are up, you can relax.

That's not strictly true. They only have to post it within 14 days, it doesn't even need to arrive at your house to still be valid.

MORPH3US

Little_John wrote:

I wouldnt worry about it, ALL speedos read more than the actual speed and the difference can be quite a lot. If you want to know how much, find someone with a GPS (Tom Tom or Garmin ect) it will give you a speed reading that is more acurate get up to 50 on your car speedo and see what the gps says your going at if when your car says 50 and the gps reads 44-46 then if your going 50 or lower you should get away with it. it all depends how strict the police were being you can usually get away with 10% over the speed limit

I have Tom Tom and know what you mean about the Tom Tom reading my speed as quite a bit slower than my speedo reading it, but how do you know its not the Tom Tom etc that is wrong?

I would have thought the speedo in your car was more likely to be correct?!?

M

MORPH3US

tonys wrote:

If you see police aiming laser guns etc at you in future -brake-don't just carry on slowing down naturally.

Thats a bit of a silly thing to do IMO.

Driving under the speed limit would be a better option. Stomping on the brakes could cause a serious accident - more serious than 3 points and £60!

Throbbe

MORPH3US wrote:

Driving under the speed limit would be a better option.

I think from the description this was more of a momentary lapse than an intention to ignore the speed limit. However, you're right that it is the only failsafe way to avoid speeding fines.

Now, who wants to buy "Throbbe's guide to avoiding parking tickets". Bargain price of £5. :rotfl: