merge in turn 1544

You appear to understand the effects of queues, but not the cause. buttuming a constant rush-hour flow of 2-lane traffic into a 1-lane section, there will always be a queue. This will probably result in traffic becoming stationary further back down the road.

Certainly, if everyone in lane 1 never allowed anyone to merge, this would be fastest for those in lane 1. OTOH, by preventing L2 drivers merging to L1 at speed, they bring L2 to a halt. Eventually someone will be let out of L2 (or force their way out of L2), causing L1 to come to a halt, etc.

That's why zip merging is a good idea. You realise that by "delaying traffic in L2" for long enough you are actually stopping traffic in L2? And by stopping traffic in L2, you are creating a larger one-lane section of road? All that happens is the blockage gets longer, so both lanes slow down further from the site of the lane closure.

Every car in L1 that fails to pull onto the hard shoulder to let you past will also delay your arrival at point A. The problem is that two lanes become one, so some drivers MUST merge. There is a queue, so someone (lots of people, in fact) will be behind EVERY merging driver. Your statement is logically correct, but unhelpful.

So? You cannot require every driver in L2 to merge behind every driver in L1, it is a physical impossibility.

How can you attempt to prove that zip merging is bad using some strange mathematics, then say you agree that zip merging is best? Either you accept that your maths is meaningless numbers, or... I'm at a loss to understand what you're doing...

Why can they drive past a long queue? When did this queue form? How did it form only in L1, leaving an empty L2?

In order to prevent someone merging behind you, you need to close the gap. Generally, you need to acellerate hard then brake hard. This causes waves of braking, leading to traffic behind you coming to a halt. This causes more delay (and pollution, fuel use...) than driving at a steady speed, leaving a sufficient gap for others to merge from other lanes without you slowing down. This is better than blocking all merging drivers, as someone would eventually allow drivers from the stationary L2 to merge, requiring L1 to slow.

-- David Taylor