Question of the week: Why doesn't zip merging work in the UK?
Fri, 23 May 2025
Dear Honest John,
"On my regular commute I have to pass a set of roadworks with two lanes merging into one and despite the sign saying 'merge in turn' it's always a bun fight of people queueing up too early and others bombing down the outside and shoving their way in at the end.
Why doesn't zip merging seem to work in this country? Don't get me started on queueing in pubs!"
- TT
Dear TT,
Zip merging, like social media and democracy, is a great idea in theory but the reality is somewhat less successful.
The theory goes that where two or more lanes merge down to one, traffic makes full use of all the available lanes up to the point where the lane is closed, thereby making full use of the available road space to reduce the length of the queue and speeding everyone's passage through it.
The reality though is quite different, as you have experienced yourself. Maybe it's the British obsession with queueing that sees drivers gather in the lane remaining open as early as possible, making the queue longer. And then other drivers try to take advantage of this by racing to the merge point as quickly as possible along the empty lane.
In a perfect world both lanes would be occupied by an even number of cars. Drivers would avoid the temptation to get right up to the bumper of the car in front and leave space for others to merge, thereby keeping both lanes flowing - it might be at very low speed, but it's still quicker than stationary.
Unfortunately this dream scenario requires everyone to play by the rules and be considerate of others, which seems like a massive ask. A bit more of that would get everyone to their destination more quickly.
