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RS1T

Original Poster:

20 posts

31 months

[news] 
Wednesday 13th June 2012 quote quote all
I drove by a speed camera at below 30mph, and within the white lines I accelerated to what my speedometer read as 32, and saw the camera flash. I do however know that my speedometer always overestimates, or so my TomTom says. In fact, after I was flashed I drove at what the speedometer says is 32 and the TomTom said it was 30.

What do you guys think? Do speed cameras ever flash when you aren't actually breaking the limit? Also, isn't there a 10% leeway on speeding as well?

I'm worried sick as I'm a younger driver, any info would be much appreciated.

LiamB

6,426 posts

26 months

[news] 
Wednesday 13th June 2012 quote quote all
Don't they flash twice if you're caught?


SS2.

7,945 posts

121 months

[news] 
Wednesday 13th June 2012 quote quote all
Little else you can do other than waiting to see if the Registered Keeper of the vehicle receives a Notice of Intended Prosecution within the next fortnight..

RS1T

Original Poster:

20 posts

31 months

[news] 
Wednesday 13th June 2012 quote quote all
It's gonna be a long two weeks...But does anyone know the answers to my two questions?

Heathwood

1,544 posts

85 months

[news] 
Wednesday 13th June 2012 quote quote all
Did it flash the front or the rear?

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RS1T

Original Poster:

20 posts

31 months

[news] 
Wednesday 13th June 2012 quote quote all
Flashed the rear, and flashed twice, possibly three times, but definitely more than once.

Heathwood

1,544 posts

85 months

[news] 
Wednesday 13th June 2012 quote quote all
Any possibility the camera picked up another driver or was it just you on a single carriageway?

streaky

19,311 posts

132 months

[news] 
Wednesday 13th June 2012 quote quote all
They can be falsely triggered. There is a secondary check, which should weed out such false positives ... but not always.

Streaky

PS - waits for the forgetful ex-member of the Engineering Council to deny both these statements - S

Stoofa

479 posts

51 months

[news] 
Wednesday 13th June 2012 quote quote all
There are guidelines....oficially no "ley-way".
If a 30mph camera fpashed you will have been travelling at an indicated 35+
There is always a delay between seeing a flash and looking at the speedo - time enough for you to see a speed slower than you were travelling.

If you're sure you weren't speeding - then a NIP you will not receive.

RS1T

Original Poster:

20 posts

31 months

[news] 
Wednesday 13th June 2012 quote quote all
Yes it was possible, there were cars both in front and behind me, but I'm pretty sure it flashed me.

Stoofa, are you 100% sure that it's 35+?

Who me ?

5,103 posts

95 months

[news] 
Wednesday 13th June 2012 quote quote all
RS1T said:
Yes it was possible, there were cars both in front and behind me, but I'm pretty sure it flashed me.

Stoofa, are you 100% sure that it's 35+?
ACPO "guidelines " were 10% +2mph=35 mph.
BUT TWO ways of avoiding.
1) ,NEVER ASSUME that speedo reading is accurate. I drop to an indicated 28 in the "DANGER ZONE" ,and have no nasty mail .( in fact, I've found that after the halfway point ,you're safe, as they need two photos, and after the halfway point they can't get a second one)
2) NEVER ASSUME that any SCP is going to do the secondary check.OK-it's ACPO guidelines ( now where have we heard that guff before?) , but I'd wonder how many speculative tickets get sent out for punters to roll over and pay, in the hope that all in the photo would cough up.

If I ever see a camera flash me, I'd note date/time & my speedo reading. And if my speedo said less than 33, I'd ask for a photo.


Deva Link

26,934 posts

128 months

[news] 
Wednesday 13th June 2012 quote quote all
RS1T said:
I drove by a speed camera at below 30mph, and within the white lines I accelerated to what my speedometer read as 32,
Why did you do that anyway?

The speed detection works by radar and it calculates the time taken for the radar 'beam' to hit the car and bounce back. If you accelerate within the range of the camera then that exaggerates your speed as the time taken for the pulse to bounce back increases faster than if you were driving at a steady speed.

If you were really only doing an indicated 32 then you've absolutely nothing to worry about. However, forget about the 10% thing - since the rules changed and they can't keep the fines, more and more safety camera partnerships are offering people speed awareness courses which they run internally. It's job creation for local retired coppers.

Pooky67

535 posts

42 months

[news] 
Wednesday 13th June 2012 quote quote all
I've seen cameras (ok one particular camera near me) 'miss flash' all the time. It goes off when cars are crawling past and even when no cars are in front of it! If you're sure you weren't speeding you'll be fine.

Super Slo Mo

3,051 posts

81 months

[news] 
Wednesday 13th June 2012 quote quote all
Deva Link said:
Why did you do that anyway?

The speed detection works by radar and it calculates the time taken for the radar 'beam' to hit the car and bounce back. If you accelerate within the range of the camera then that exaggerates your speed as the time taken for the pulse to bounce back increases faster than if you were driving at a steady speed.

If you were really only doing an indicated 32 then you've absolutely nothing to worry about. However, forget about the 10% thing - since the rules changed and they can't keep the fines, more and more safety camera partnerships are offering people speed awareness courses which they run internally. It's job creation for local retired coppers.
They don't really work like that, they use the frequency shift (heterodyne principle I believe) to determine speed, and only need one 'ping' to get you.

When they were originally installed, the cameras had a 'user' set threshold of between 6 and 26 mph over the limit. I believe it's been tightened a little now, but there's still a comfortable margin between the posted speed limit and the trigger speed of the camera (says he, 10 days after being flashed, and still waiting for the NIP but I was definitely over the limit, and kicking myself for failing to observe the camera, oh well)

craigjm

3,152 posts

83 months

[news] 
Wednesday 13th June 2012 quote quote all
Has the camera been there long? quite often when they are on "test" they flash randomly regardless of speed.

RS1T

Original Poster:

20 posts

31 months

[news] 
Wednesday 13th June 2012 quote quote all
Thanks for the replies guys, this will make me sleep a bit easier tonight. If I do get a letter, I'll be sure to ask for the photo. Not much else I can do, but thanks anyway wink

JumboBeef

2,373 posts

60 months

[news] 
Thursday 14th June 2012 quote quote all
I got flashed by a red light camera once.....even though I had stopped correctly, just before the line. It worried me so much I turned around and approached the same lights from the same direction. Again I stopped, and again I got flashed hehe

Must have been some sort of fault.

TheTurbonator

2,092 posts

34 months

[news] 
Thursday 14th June 2012 quote quote all
My Dad once got flashed by a Gatso when travelling in the opposite direction. Deserted country lane with no other cars in site, so was definitely his car that set it off.

He was speeding at the time (about 45mph), as it's one of those silly 30mph zones on a deserted quiet country lane limits. I don't know if it was his speeding that triggered it or whether it was just his car and his speed had nothing to do with it.

I have heard that caravans have a tendency to set Gatso's off randomly. Don't know if it's just rumour or not though.

liner33

4,062 posts

85 months

[news] 
Thursday 14th June 2012 quote quote all
JumboBeef said:
I got flashed by a red light camera once.....even though I had stopped correctly, just before the line. It worried me so much I turned around and approached the same lights from the same direction. Again I stopped, and again I got flashed hehe

Must have been some sort of fault.
My mate did this in Germany , got flashed once when stopped and then tried again and got flashed going through on green , got two fines though the post due to him clearly not wearing a seatbelt!!

walm

4,407 posts

85 months

[news] 
Thursday 14th June 2012 quote quote all
Deva Link said:
The speed detection works by radar and it calculates the time taken for the radar 'beam' to hit the car and bounce back. If you accelerate within the range of the camera then that exaggerates your speed as the time taken for the pulse to bounce back increases faster than if you were driving at a steady speed.
Physics fail.
Radar is perfectly capable of measuring the instantaneous speed of accelerating objects.
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