M4 gantry speed camera
Discussion
Hi. Just driving home on the M4 Eastbound from work toward Newport up the hill past Tredegar park, past the High Cross turning down the hill toward the Malpas turning, one of the gantry cameras flashed as I went through doing about 51mph, another car past me at the same time doing about 55 - 60mph, National Speed Limit Applies on the matrix signs before this gantry and i'm more than certain there were no speed limits showing on the said gantry. The gantry after this one just before Malpas was showing 50mph. I don't understand if not showing a limit why it would flash. Faulty or could a limit have just came into operation as we drove through?
Bloody two week wait now checking the post
Bloody two week wait now checking the post
We have had many discussions on this, and many responses from Highways England. The replies have all said, if a gantry shows no reduced speed limit, then (even it is within a reduced limit, i.e. the gantry shows nothing and fails to match the before and after reduced limits) the gantry will not flash. So, for now, there is little need to worry.
Pica-Pica said:
We have had many discussions on this, and many responses from Highways England. The replies have all said, if a gantry shows no reduced speed limit, then (even it is within a reduced limit, i.e. the gantry shows nothing and fails to match the before and after reduced limits) the gantry will not flash. So, for now, there is little need to worry.
Do Traffic Wales work to the same standards as Highways England???speedyguy said:
Pica-Pica said:
We have had many discussions on this, and many responses from Highways England. The replies have all said, if a gantry shows no reduced speed limit, then (even it is within a reduced limit, i.e. the gantry shows nothing and fails to match the before and after reduced limits) the gantry will not flash. So, for now, there is little need to worry.
Do Traffic Wales work to the same standards as Highways England???Fury RS said:
Hi. Just driving home on the M4 Eastbound from work toward Newport up the hill past Tredegar park, past the High Cross turning down the hill toward the Malpas turning, one of the gantry cameras flashed as I went through doing about 51mph, another car past me at the same time doing about 55 - 60mph, National Speed Limit Applies on the matrix signs before this gantry and i'm more than certain there were no speed limits showing on the said gantry. The gantry after this one just before Malpas was showing 50mph. I don't understand if not showing a limit why it would flash. Faulty or could a limit have just came into operation as we drove through?
Bloody two week wait now checking the post
It doesn't matter what speed limit is on the gantry before and the gantry after the gantry with the camera on. Only the relevant gantry has the speed limit that the camera is enforcing. Bloody two week wait now checking the post
The cameras on the M4 are linked electronically to the sign and it is the illuminated elements in the sign that sets the speed limit on the enforcement camera. Only the speed limit value illuminated by the illuminated, non-illuminated in the case of NSL, sections of the sign can be set on the speed camera.
If it has flashed at 60mph the limit must have been illuminated at a value of 50mph or less. It cannot flash at a vehicle speed of 60 or less if the sign is not illuminated.
Repel_Max said:
It doesn't matter what speed limit is on the gantry before and the gantry after the gantry with the camera on. Only the relevant gantry has the speed limit that the camera is enforcing.
The cameras on the M4 are linked electronically to the sign and it is the illuminated elements in the sign that sets the speed limit on the enforcement camera. Only the speed limit value illuminated by the illuminated, non-illuminated in the case of NSL, sections of the sign can be set on the speed camera.
If it has flashed at 60mph the limit must have been illuminated at a value of 50mph or less. It cannot flash at a vehicle speed of 60 or less if the sign is not illuminated.
Did you tell us that when the limit changes, the camera does a flash-flash to calibrate (or some such thing) or did I imagine that?The cameras on the M4 are linked electronically to the sign and it is the illuminated elements in the sign that sets the speed limit on the enforcement camera. Only the speed limit value illuminated by the illuminated, non-illuminated in the case of NSL, sections of the sign can be set on the speed camera.
If it has flashed at 60mph the limit must have been illuminated at a value of 50mph or less. It cannot flash at a vehicle speed of 60 or less if the sign is not illuminated.
Bert
Forums | Speed, Plod & the Law | Top of Page | What's New | My Stuff