I've noticed some yellow poles with cameras on top have been erected recently on the M4 on both eastbound and westbound directions, just by Osterley heading towards the GSK building in Brentford. From your website it looks like these are either VECTOR or SPECS cameras.
My concern is there has been no signage erected notifying drivers of their operation. On the westbound side there are three regular style cameras (GATSO and SpeedCurbs) which do have appropriate signage. Are these new cameras covered by existing signage? Why has there not been any notification on any gov websites about their operation? I can't seem to find any info around them.
April 2017 update: A motorist comments... I've dome some further research and I believe I've discovered their purpose. There are roadworks scheduled for the implementation of the so called Smart motorway upgrade. My source is the following forum PepiPoo where its been discussed. There being only to reader heads per gantry arm supports the believe it will be used in relation to roadwork's with reduced carriageway numbers.May 2017 update: The older Gatso speed kameras have been taken away from the M4. Now there are Variable Speed Cameras starting before the Heston Service (after J3) Eastbound and continues all the way, up on the flyover to the end at J1 where M4 becomes A4. (I don't know if continues further in on the A4).
First Camera at Heston, two more before the flyover starts, and 3 points on the flyover. They all are small yellow kameras, singles on a few points and doubles on the flyover (2 lanes).
There are also cameras westbound on the flyover starting at J1 and last kamera right now is spotted at the end of the flyover before the National speed limit signs.
The road have variable Speed limits.
