Zipper methodWorldwide
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331. Zipper method
The zipper method, also called zipper merging, is a way of merging traffic when one or more lanes end or become blocked. Drivers use the available lanes up to the merging point and then enter the continuing lane alternately, like the teeth of a zipper.
The method is especially useful in slow or congested traffic because it makes full use of the available road space and creates an orderly merging pattern. Drivers should avoid merging too early when zipper merging applies.
Wikimedia.org • Adrian Grycuk • CC BY-SA
How does the zipper method work?
Where the local zipper-merging rule applies, drivers use the available lanes up to the required merging point and then merge alternately into the continuing lane. Follow the signs and national rules; do not apply this pattern automatically at every joining road or motorway entrance.
🔗 gov.uk • Great Britain Highway Code, Rules 159–203, manoeuvres; national guidance example
🔗 gov.uk • Great Britain Highway Code, Rules 133–134, low-speed merging; national guidance example
🔗 gov.uk • Great Britain Highway Code, Rules 238–252, parking; national guidance example
Does zipper merging apply whenever two roads join?
No. Zipper merging generally applies in specific lane-reduction or obstruction situations. Normal priority and merging rules continue to apply where separate roads or entry lanes simply join unless national rules provide otherwise.
🔗 gov.uk • Great Britain Highway Code, Rules 159–203, manoeuvres; national guidance example
🔗 gov.uk • Great Britain Highway Code, Rules 133–134, low-speed merging; national guidance example
🔗 gov.uk • Great Britain Highway Code, Rules 238–252, parking; national guidance example

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