Specs on M25 Junc 2/3 Clockwise

[roosevelt]

Anyone know if these are in operation yet? Was on M25 leaving the 50mph limit to NSL just prior to Junc 2 entry sliproad when noticed more specs (no s/l displayed on main carriageway..) Looks like roadworks in progress at certain times of the day..
(Also on other side of carriageway - Junc 3/2 Anti-Clockwise)

Also, Junc 28 to 27 Anti-clockwise have been monitoring for sometime.. do these only operate when roadworks in operation ie lane closed??

Ta