In message , Harry Bloomfield
writes
NY has brought this to us :
Any fool can make zip merging safe, but it takes *skill* to make it
work without imposing a very severe bottleneck on traffic flow, when
with a bit of advance warning, everyone can get into one lane without
having to slow down much and then the single stream can keep moving
through the roadworks.

That just moves the merge point further back and reduces the capacity
of the road to store waiting vehicles. Merging just in time allows more
vehicles to be in the queue, when a queue forms.

I don't like queues, do you? When the traffic merges well before it
absolutely has to, there's a far better chance of it being able to
maintain speed, and no queue forms. If left until it has to merge, there
is more chance a bottleneck occurring, and everything grinding to a
halt. And as I said, I don't like queues!
--
Ian