what does "avoid changing l;anes" mean?

[gridgway]

that is the wording I believe for when the m25 vble speed limit is in force. What exactly does it mean? Does it mean literally suspend the normal lane discipline and stay where you are unless you need to change lane to leave the motorway or similar?

Graham

[rsvmilly]

In the average speed limited roadworks it appears to mean all drive three abreast at 40mph, regardless of what's on the road.

[MrKipling43]

I guess, from the dreaded health and safety point of view, they reckon that if cars aren't weaving around there's less chance of one of their workers getting wiped out.

[saxmund]

I presume it means don't change lane on a whim or to try to gain a few feet on another car. On a congested road, lane changes cause other motorists to brake, thus causing bunching and worse jams. If everyone generally stays in lane, then the traffic continues flowing. If there's a speed limit, and your travelling at it, there really is no need to change lane. It's simple really.

[DanH]

saxmund said:

I presume it means don't change lane on a whim or to try to gain a few feet on another car. On a congested road, lane changes cause other motorists to brake, thus causing bunching and worse jams. If everyone generally stays in lane, then the traffic continues flowing. If there's a speed limit, and your travelling at it, there really is no need to change lane. It's simple really.

And it's much cheaper than spending money on building the necessary road infrastructure. Not to mention politically convenient to play on middle class environmental guilt when you really should be putting in more lanes.

[gridgway]

so is it an official change of driving behaviour? IS it defined anywhere?

Graham