In Wallonia, one quarter of drivers do not know how to apply the zipper principle, according to a VIAS Institute survey performed at the five-year mark of the measure being included in the road code. VIAS institute is a major Belgian knowledge centre that aims to improve road safety, along with mobility and safety in general.
In traffic engineering, the zipper principle is a convention for merging traffic into a reduced number of lanes. Drivers in merging lanes are expected to use both lanes to advance to the lane reduction point and merge at that location, alternating turns.
Overall, 97% of Belgian drivers have already heard of the zipper principle: better known in Flanders (99%) than in Wallonia (94%) and Brussels (96%).
But even if it is true that more and more Belgians know what this principle is, one in five drivers still does not know how to apply it correctly, the main mistake is to think “they should fall back as soon as possible instead of going as far as the obstacle,” VIAS points out. Walloons are the least to apply it correctly (73%), compared to the Flemish (86%) and in Brussels (74%).
81% of drivers nationally consider the zipper mechanism as effective, while one out of five Walloons disagrees. Nearly four drivers out of 10 also notice daily a wrong use of the zipper and 80% are annoyed by this.
Finally, more than a third (37%) of Belgian motorists apply it every day. In Brussels, not quite half would use it daily.
“The zipper principle is to be applied where a lane is interrupted and causes traffic to slow sharply,” VIAS Institute CEO Karin Genoe recalls. “The driver must keep going in his lane until he can merge where traffic continues. Drivers must alternate.”
“Note that the zipper principle is based primarily on courtesy and allows to use maximum road capacity in case of lane reduction. Everyone wins if it is implemented correctly,” VIAS CEO concludes.