On Sat, 3 Aug 2019 10:44:04 +0100, Ian Jackson
wrote:

In message , Harry Bloomfield
writes
Steve Walker brought next idea :
whereas merging at the pinch-point often means cutting into a small
gap, causing those behind to brake and the ripple effect to bring the
whole road to a halt or slowing to a stop yourself and holding up the
traffic behind.

Not if the merge is orderly and with cooperation from both lanes, which
is what you get as a result of no one being able to bypass the queue.

Early merges, leave one lane less than fully occupied and space for the
impatient to bypass the queue.

What you're saying is that late, 'co-operative' mergers force the
'unco-operative' would-be queue-jumpers to 'co-operate'. Well, this is
true - but it often leads to a log-jam at the pinch-point, and that
creates tail-backs that probably would not have happened if everyone had
merged early, and (if possible) maintained speed.

We did this very thing earlier, merged (pretty well) *at* the
long-standing pinch point because it is generally relatively slow
moving traffic (30-40 mph), the ramp up to the point quite short and
traffic light enough for it to continue to work well.

Well, in actual fact we were on the inside and 'priority' lane and
those in the outside lane have to merge (and so 'co-operate') with us.

Today they did, in the rush hour it's yer basic zip (respected by all
but the odd van and some flash boys (typically) trying to take the p)
and a mix of effectiveness at speeds / loads in-between. The bunching
only generally occurs when people in the outside lane try to overtake
into the pinch point, where is blatantly nowhere for them to go. To
resist that (for the benefit of all, even the w&nkers, if only they
could see it), many will start to straddle the line early.

Cheers, T i m