Safe Speed Forums

Hi chaps,

Next Monday, Inside out, BBC1, 19:30hrs will be airing a programme containing information with regards to innocent drivers in London being 'caught' speeding by mobile cameras in London. Unit in question appears to be the Lit-20-20 and a study with this camera appears to indicate that it is far from accurate. In other words, it the programme highlights indicate that innocent motorists are being prosecuted due to an innacurate speed measurement device.

There is limited information at the moment, i'll record it to DVD and send some copies to Paul.

I've been working with them on it for months. I even filmed an interview for it in Exeter, but they ended up with 40 minutes of finished video for an 8 minute slot and I got cut.

It will show in London and BBC South West areas simultaneously.

I reckon it's devastating, but I don't know how much I can say. It's long been secret. I'll check with them tomorrow.

_________________
Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

It's a shame that it has been condensed so much. I think from the taster it would appear that it will indeed be devastating for the scamera partnerships. If it's as bad as it seems, they'll never be trusted again ever.

Even supporters wouldn't be able to defend the indefensible.

It may be a week later in the rest of the country. If you have sky via a dish will be on BBC ONE SOUTHWEST. 957. next monday.

I had to wash my car

not

Are you saying it's not true, or are you just wishing it would go away?

i get to many E03 error readings to know that the camera does not give false readings as suggested by the slide effect

Interesting logical leap of faith there.

How do you know the non-error readings are accurate? I'm not quite picking it up from what you wrote.

Your statement could keep a student of Logical Fallacy busy for months.

ok

The equipment is type approved - Doesn't say anything about an individual unit or how it is operated. The fact that the TA documentation is a state secret could cause some to raise an eyebrow.

Calibrated - Doesn't say anything how it is operated or problems inherent in the device type.

Various checks carried out prior to enforcement - As above.

Self checking after every log - No Comment

Your points do not have a cumulative quality assurance effect.

It'd have to be a poor student...

Evidence of some errors does not mean that all errors are identified.

_________________
Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

I'll comment: this amounts to a circular argument because the checking system uses the same input that it is supposed be checking.

Camera Operator: have you seen this? The LTI reads 77 then 85 then 107 then 87 in about 7 seconds, and he was prosecuted for 107mph.

How on earth did that video obtain a conviction?

Other side of the carriageway, multiple reflective signposts, obstructions, LGV coming the other way, Timeout error flashing, unstable operation, no markings to confirm reading.

Lastly, as the speed shown was -107mph (a negative speed) then it would appear to me that this device isn't designed to be read with the traffic moving away from the camera.

Oh, i've just seen the stills and it appears that there was an error 02 and 03.

MAD

Someone on this site posted links to videos of three lasers, including an LTI20-20, getting speed readings of stationary objects apparently by means of slip/slide. It's a bit late so I'm not going to look for 'em now, but trust me, I've seen them. How do you account for what seems like false readings from slippage on these videos? Does the lack of errors not give you any concern that a flase spped reading on your equipment may not be accompanied by an error message too?

_________________
Make everything as simple as possible, but not simpler - Einstein

I too have seen slip errors. cars in the car park moving at 12, 14 miles per hour and then we caught a telephone exchange moving. Inside out point at a stationary car and get a reading as another car passes (on the trailer for the program) they were on the edge of the car... any way judge after you have seen the program.

is

i

I believe it's within the SouthWest and London areas.

I think the reason you don't get slip effect is because you point the kit then squeeze the trigger.

Lets be clear we were using it incorrectly, but wrong speeds were detected. This was nothing to do with any tv program, it was in a carpark after going to court. (lorry tacho & gps v lti20/20 , the case continues!)

In-correct readings happen when the kit is moved around from target to target with the trigger squeezed or very long distances where a small camera shake causes the laser to move a much larger distance.

We found there was a technique to getting a wrong reading. a smooth sweep was required and I was told that a slight angle on the kit helps.
However after a min or two they were popping up every other time. this requires setting the target speed to zero. The makers of the lti20/20 cleverly designed it so it does not display car speeds that are complying. This hides the accidental errors when they occur. There is some error detection but on our lti20/20 we could beat it. It may not have had the most recent firm ware. It was not in curent service and did not have a callibration certificate.

I would be interested to try out the method of getting reflected readings.

I have no doubt that some camera opperators get no wrong readings and others get a lot. Pointing at a road sign is a lot easier than a moving car at 300m.

anton