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FightBack Forums > Queries > Speeding and other Criminal Offences
Tomsta
What if the first Gatso photo shows the vehicle with the rear axle at the end of the road markings & the second photo shows the whole of the vehicle having passed the end of the road markings i.e no wheels on any road marking.

Can you still be prosecuted on the evidence of just the laser (or is it radar?) without the use of both photos showing the vehicle on the white road markings?

I have yet to see the photos, so can't post them.
bama
lets see the pics. from what you say the first one has the vehicle on the last road marking and then on clear tarmac.
yes ?

scrub thephotos before posting !

Host them on Tinypic please (less problematic than other well used hosts).
desktop_demon
ah, Gatsos, doncha just love em.....

The gatso "primary" speed estimation is done by Doppler radar. The secondary check is done via photogrammetry performed on the two photographs. The secondary check is just that and should not be used as evidence of speed (although if desperate the CPS has been known to try).

The radar speed is printed in the "data block" of the first photo along with some other information. That should be within 10% of the speed estimated from the secondary check on the photos.

The secondary check is a classic (distance travelled)/(time taken) calculation. The time taken between the two photos is usually 0.5 seconds but the value should be printed in the data block of the second photo. The markings on the road should be physically measured but would probably be either a 2m or 5ft marker separation. 2m is more common now I believe. Using this information you should be able to more accurately estimate the vehicle speed.

The idea that the gatso gives different results for accelerating (or braking) vehicles holds some weight - but not too much! If the vehicel is braking VERY hard or accelerating like a rocket then the GATSO should REJECT THAT reading - or that is what is said to happen by those in the know. otherwise the 0.5 second timing is selected so that "normal" acceleration or braking will not substantially affect the reading - certainly not enough for the secondary check to fail.

However GATSOs can fail to give reliable results (yes, you alway knew it was true..) that is an established and agreed fact. So sometime (just sometime...) the photos can reveal a malfunction of the system and an invalid allegation of speeding.

Good luck!
Hotel Oscar 87
...and for the avoidance of any conceivable doubt there speaks a man who took the Gatso on - and won. Inspite of the utter nonsense and frequent use of terminological inexactitudes by a prosecution that finally tied itself into one large knot. notworthy.gif
bama
One interesting thing will be to see if the manula check of the photos was done at all - after all 'bad photos' are not supposed to go out, but we all know that any checking is every Preston Guild.
Tomsta
Thanks for the replies.

Should get to see the photos tomorrow.
Tomsta
O.K, I've seen the very poor quality photocopies of the pictures that the registered keeper was sent by the kind folk at Safecam.

Three photocopies, one of which is a substantial enlargement to show the vehicles rear no. plate.

The quality is dreadful & in the second photo (taken 0.6 seconds after the first) it's not possible to accurately tell if the vehicle has passed the end of the "dragons teeth" markings. It would appear likely that it has. But without a better quality pic, it's not possible to say for sure.

You can't see any of the interior of the vehicle (a slab sided vehicle with large rear window) thus making any verification of who was the driver impossible.

So, how important are the photos? desktop-demon's excellent post above would imply that they're not.

It says on the Safecam website, "It must be stressed that the secondary checks marks are there to safeguard the motorist against a faulty or false camera reading. The speed given in any prosecution is the speed recorded by the camera."

But I'm not naturally inclined to believe all they say!

If the photos are required for a successful prosecution, then the RK will request better copies.

If not, I guess the driver will have to endure 3 hours of listening to how "speed kills" etc. on the safety aware course. Better than 3 points I guess, as the recorded speed was 36mph in a 30mph zone.

Fortunately nobody was killed or seriously injured!!!!!

QUOTE (bama @ Tue, 26 May 2009 - 22:03) *
lets see the pics. from what you say the first one has the vehicle on the last road marking and then on clear tarmac.
yes ?

scrub thephotos before posting !

Host them on Tinypic please (less problematic than other well used hosts).


Sorry bama for not replying, yes that's correct.

No point posting the pics. as the quality is too poor to ascertain the above.
bama
Now I am lost, the shots show "the first one has the vehicle on the last road marking and then on clear tarmac."

but are too poor quality to show that "the first one has the vehicle on the last road marking and then on clear tarmac."
The Rookie
Can you wash and post the pics, as bama says what you say is contradictory.

Not being able to ID a driver from teh pic is irrelevant, you know you were driving.

Have a look at Griffiths http://www.bailii.org/ew/cases/EWHC/Admin/2007/619.html

Simon
Tomsta
Photo 1 : Shows the vehicle on the road markings. The road markings nearest to the camera are clearly visible, but fade in quality near to the rear of the vehicle.

Photo 2 : Shows the vehicle but the O/S road markings are not showing for some distance (a cars length at a rough guess). The N/S road markings are clearer. But not clear enough to tell for sure if the rear of the vehicle has just passed the last of the markings.

I think that the rear of the vehicle is either very close or just beyond the last of the road markings.

The quality of the photocopies is so poor that it's just not possible to be sure.

It's not worth posting the pics as you'll be no wiser than me.

Only a better quality photocopy or the original photos will show the truth.

But before the RK asks for a better quality set of copies, please could someone tell me if the photos are critical to the prosecution & if so the implications of the vehicle in the last photo being past the road markings.

If they're not, the driver will accept the £60 fine & attend a "speed kills" awareness course.

Many thanks.

Tomsta
QUOTE (The Rookie @ Fri, 29 May 2009 - 08:19) *
Can you wash and post the pics, as bama says what you say is contradictory.

Not being able to ID a driver from teh pic is irrelevant, you know you were driving.

Have a look at Griffiths http://www.bailii.org/ew/cases/EWHC/Admin/2007/619.html

Simon


Thanks for your reply.

In point 37 of the above case, it appears that the secondary check must tally with the primary check.

If this is the case, but the vehicle has passed the road markings in the second photo, perhaps a prosecution couldn't be valid as the secondary check would not be entirely accurate.
The Rookie
The road markings are not required to preform the secondary check, they just make it a lot easier, so even if teh car is beyond the markings, the prosecution could still succeed.

As you say, the markings may be more obvious in the original than in the copy, why not return to the 'scene of the crime' and look at the angles and you'll be able to see where the markings fall relevant to the cars position in respect of other features.

Simon
desktop_demon
The primary speed given by the Gatso is calculated from the doppler radar retuned signal shift. Which means for legal purposes that reading is the speed used for any prosecution. if the accuracy of the camera is in doubt then a secondary check can be performed using the photographs to estimate the speed. This process is called photogrammetry - measuring distnace using a photograph. The speed calculated from the photogrammetry MUST be within 10% of the speed calculated by the radar. If it is not then the Gatsometer evidence, in its entirety, is inadmissable at trial. Which can be a big problem for the prosecution.

So the photos are not necessary to prove the speed of the vehicle - but they are neccessary to check and confirm the camera itself is working correctly. if it is not working correctly then the evidence it produces cannot be relied upon.

I hope that explains the situation regarding the photographs and the speed alleged.
Tomsta
Thanks desktop-demon.

Great explanation, but it doesn't answer my question re: the rear of the vehicle being past the road markings in the second photo.

If the rear of the vehicle has passed the end of the road markings, does this mean that an accurate photogrammetry calculation can not be made?

If so, it wouldn't prove that the radar was faulty or inaccurate, it would just mean that there wasn't an accurate secondary check to check the camera!

What are the implications of this?
nemo
QUOTE (Tomsta @ Fri, 29 May 2009 - 12:49) *
Great explanation, but it doesn't answer my question re: the rear of the vehicle being past the road markings in the second photo.

The Gatso Type 24 was originally granted approval by the Home Office without painted timing marks - the secondary check was provided by means of photogrammetry.

This method proved to be very labour intensive and the police subsequently sought (and were granted) approval to introduce and use painted timing marks.

The original method of providing the secondary check (without timing marks) was never revoked and remains valid to this day.

desktop_demon
The marks on the road are not actually needed to do any photogrammetry - they just help it to be done more easily than without marks. So no marks to reference by is not a significant defence in itself.

BUT that depends on how you run your defence (if you decide to do that). If you ask the camera technician to manually repeat the measurement and speed calculation on the witness stand using such photographs then you can appreciate he/she will have problems doiing so. The speed may not be shown to be as alleged beyond reasonable doubt.

But don't rely on this alone to be an absolute defence - anyone can make an estimate (you too!) and try to come up with a realistic and practical figure for the speed judged from the photos. Be aware that this will happen and if you have no better argument than you cannot do the speed estimation yourself - your case may have difficulties. So at least try to estimate where the vehicle is. It should be possible to make a "definately too far" and "definitely too short" estimate of distance. Your true answer will be in between. If neither speed helps you defend the case then maybe best to accept the early plea. if one or both the higher and lower estimates yield useful results then you have a chance to rebutt the allegation.
Tomsta
Thank you so much, that's very useful & interesting.

Why did the camera film the vehicle once the vehicle had already passed so far down road the markings, bearing in mind that the alleged speed is 36mph?

I thought, perhaps incorrectly, that the camera is triggered when the rear of the vehicle (exceeding the speed limit) passes the first road markings. Am I wrong?

I'm wondering if the camera has not been set/aligned correctly with the road markings.

The RK has requested that they see clearer copies of the photos, which apparently has resulted in some confusion & a "manager" is going to telephone her. Interesting!
Tomsta
Oh dear the RK has been emailed the photos. Although the quality is still poor, it's now obvious that the rear of the vehicle is just within the end of the road markings.

So it's not worth pursuing.

Oh well, thanks to everyone who replied & I for one have learnt more about Gatso's & road markings, hopefully others have found it helpful.

The Rookie
I think that was what we were telling you was probably the case all along!

You can still carry out the time/distance check to confirm that he radar speed is correct.

Simon
desktop_demon
yes - once you have the photographs from the gatso - ALWAYS carry out a secondary check. Try to estimate the distance moved and using the elapsed time calculate the speed. 1m/s=2.269mph so it should be easy enough to do the calculation. The photo speed must be within 10% of the radar speed or the evidence is inadmissible. If you are unsure "wash" the pictures and post up here.

And just to show it does happen - I have just recently spotted another set of gatso photos that are so close the the error limit that it is worth contesting on that point alone. I cannot believe (on a statistical basis alone) that the gatso that flashed me was the only suspect gatso in the world!
bama
as we well know the photos do not get manually checked before issuance as they should be. Always worth a look.
Dr Science
QUOTE (Tomsta @ Fri, 29 May 2009 - 14:12) *
So it's not worth pursuing.


Au Contraire.

You need to perform the secondary check, it may well turn out to be wrong.

You said:
QUOTE
What if the first Gatso photo shows the vehicle with the rear axle at the end of the road markings

Just how far into the markings was the vehicle?

You see, the camera should fire 200 milliseconds after the vehicle leaves the radar beam.

The vehicle should leave the beam just before the vehicle enters the markings, so the first photo should be pretty much right at the first mark. If it is not, either the vehicle is going very fast, the markings are painted over a much longer distance than usual, or something is mis-aligned or not working properly.

If the first photo shows the vehicle well into the markings then its well worth doing the second check and well worth having someone who knows Gatsos well take a look at the photos and the Google aerial photo of the site. Drop a PM if you don't want to discuss it publicly.

Dr.S
Tomsta
Thank you for the replies.

It's tricky to be really accurate on the 2nd photo as the road markings are only on the n/s the o/s markings have been tarmaced over!

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