I realise that your comment was a light-hearted one, but it does raise an important point to bear in mind about motorway congestion.Gareth Thomas wrote: ↑Sun Sep 05, 2021 22:36 Although, using the M25 today Junction 11 seemed to be the hot spot. Queues in both directions leading to it and clearer roads afterwards. Who knew Woking was the place to be?
Observed queuing is easy to misinterpret. Owing to driver and vehicle behaviour amplifying a trivial defect in the normal flow, and the resultant compression wave travelling upstream from the trigger point, queueing locations are quite dynamic. The disturbance usually originates near an interchange (either a merge or diverge), but it can propagate far upstream and so obscure the real cause. You may encounter severe queuing, even standstill, which soon evaporates; and then you unknowingly sail freely through the location that actually caused it. We've all experienced that.
Regardless, it's also true that one pinch-point can cause queues that encompass up to three junctions upstream. I've been monitoring the congestion at M25 J9-J16 for a few days (from afar, using google maps' live and typical traffic settings - but I do have real M25 familiarity too). There appear to be two probably-independent lengthy clockwise queues at the worst time (17h00 Friday), though the two can join up.
One queue runs from just before J13 to just after J15. I'm sure (from watching it build up) that its root cause is the too-short weaving length between J14A and J15, and the 3-lane pinch through J15. A braided re-modelling from J14 to just north of the stack, might cure it. There's easily sufficient space.
The other clockwise queue begins at the Cobham Services on-ramp and dissipates shortly before J12. The main cause is J11 lane drop. Time for ALR, including over the bridge?