Today on the A580 I reached the stop line in lane 1 at a box juction that has one of these red light Gatso cameras just as the lights turned to amber. I was doing 20 (in a 50 zone) and had a vehicle too heavy to safely stop without skidding or shifting its load (around 30 tons gross vehicle weight) so continued, as the lights were amber. The lorry in front slowed on the junction, appearing to miss a gear change, forcing me to slow and the lights would have been on red by the time the trailer wheels passed over the trigger loops. The camera flashed twice, however there was a Mercedes in lane 2 going it some who clearly did run the red light as he would have been way behind me when I entered the junction who could have been the reason the camera activated.
I'm rather annoyed at this, having had a clean licence since I passed my test in 1997. However having searched all information I can find on the internet, I can find no reference to how the cameras deal with vehicles that have more than two axles (mine had five - two on the tractor unit, and three under the trailer) as how does it know that these are the same vehicle as opposed to two separate vehicles? I also cannot find anything that says whether the camera knows which lane the vehicle running the lights was in. Given the Mercedes passed at warp speed and my trailer was a tall reefer that would have obscured the car from the camera, would there be any evidence recorded to prove that the picture of the rear of my vehicle was in a different lane from the vehicle running the light?
All the sites I can find are assuming that you are in a car and not a very long lorry. I tend to be a worrier, and it may be that a human operative looks at the pictures first and discounts those that clearly would have activated the Gatso with rear axles on a long trailer, or have been activated by a vehicle in another lane that may not show properly in the picture. However it isn't nice having the sword of Damocles dangling over my clean licence for the next month just in case the fuzz decide to shaft me anyway. Can anyone provide any enlightenment over the way these things actually work and dish out points and fines?