revtothelimit - motorbike forum

Morning...

No, I have not set one off!!! But, On the M25 there are a lot of gantry mounted speed cams above each lane. Are these every used?

I have seen the yellow cameras are positioned at the side of the gantry flash, but never the gantry mounted ones...

Newbie73 wrote: Sat Mar 28, 2026 9:07 am Morning...

No, I have not set one off!!! But, On the M25 there are a lot of gantry mounted speed cams above each lane. Are these every used?

I have seen the yellow cameras are positioned at the side of the gantry flash, but never the gantry mounted ones...

IIRC the gantry mounted ones are the old "Gatso" type, ie fixed trigger speed.
I can't remember if offhand if I've seen one flash, but they might not have a flash.

The verge mounted ones are newer and have a variable speed trigger because they're supposed to help manage the variable speed limit restrictions on "smart" motorways. Note: they're still active when the limit is 70. I've been caught by one a few years ago. They have a small set of cameras just before them, which takes a photo of the gantry mounted speed limit sign at the same time, so there's legal proof of the temporary speed limit signs if they're lit.

A nerd notes:

The yellow on the side of the gantry are 'HADECS' - Highways Agency Digital Enforcement Camera System. Introduced in 2014.

I've seen the gantry ones flash before now - but not recently

Yoshimura make speed cams

Gantrry = behave yourself, it might have a spped camera.

Newbie73 wrote: Sat Mar 28, 2026 9:07 am Morning...

No, I have not set one off!!! But, On the M25 there are a lot of gantry mounted speed cams above each lane. Are these every used?

I have seen the yellow cameras are positioned at the side of the gantry flash, but never the gantry mounted ones...

Yes. They reset to the temp limits, too.

I've seen the gantry cameras go off a few times and like Spin says they also set to the gantry limit as saw one go off with a 40 limit set.