Motorway and signed speed limits

[mx5alive]

Can anyone advise on this question. You're travelling on any section of motorway and the overhead or barrier signs show a slower speed limit IE 50 or 30. Most of the traffic is doing in excess of this speed limit. Is the speed limit advisory or is it enforceable? Would the police stop you if you exceeded it or only if you were still doing in excess of 70?
My question came to mind today on the M65 30 mph Limit was flashing but in pretty light traffic it was obvious the road was clear ahead. Both directions had the same limit flashing but I saw nothing on either side which would require the lower speed. I appreciate there are often reasons for the change but wondered if you would get done at say 50 in the 30 zone?

[Uncle Fester]

Mostly advisory. The exception I'm aware of is M25 where they are mandatory near Heathrow. Mind you, if the matrix is flashing 30 & you hit something at 70 you'd be in deep do do!

[d-man]

I believe the signs like the variable section on the M25 (are there any others?),which display the speed limit in red circle over each lane are actual limits.

I think the sort you normally see are advisory, but I expect a dim view would be held if you ran into the back of a load of stationary traffic while ignoring them Main problem with them is half the time they're either lit up for no reason or they're blank when it would really be a good idea to show something.

[EDIT] Too Slow....[/EDIT]

>> Edited by d-man on Sunday 14th November 19:15

[supraman2954]

If I remember the HWC correctly, anything within a red ring indicates a command which you must obey. If not, then it is advisory (i.e. the small yellow matrix signs with flashing lights in the central reservation)

[GreenV8S]

d-man said:

I believe the signs like the variable section on the M25 (are there any others?),which display the speed limit in red circle over each lane are actual limits.

Yes, I believe the red circle makes it mandatory, any other sign is just advisory.

Interesting quesion: if a speed limit sign has a message underneath, does that stop it being a speed limit sign? For example the roadworks '50 mph ... 1 mile ahead' signs on motorways obviously aren't speed limit signs despite having the red circle?

[BlackStuff]

Yep, 50, 40 or 30 with a red circle round it means "obey". 50, 40 or 30 without a red circle means "look further ahead, make damn sure you can stop in the distance you can see to be clear, and do something about that tailgater before he shunts you!"