Zipper merging  – an element of road ethics or an imposed requirement?

Zipper merging is a term that often appears in the context of decongesting traffic on Polish roads. Many drivers still mistakenly believe that it is only a form of road courtesy. However, the truth is that from December 2019, zipper merging is no longer just a matter of good road behaviour. Additionally, this technique helps optimize traffic flow, especially in high-density areas.

How to zipper merge

Imagine a situation on a two-lane road with heavy traffic. When approaching traffic lights and intersections, both lanes start to fill up. When we reach a narrowing that reduces the road to one lane, vehicles from the ending lane should be let in smoothly and alternately. It is like closing a zipper – hence the name “zipper merging”. The change in regulations in 2019, made this driving method a generally applicable law.

Zipper merging – regulations

Zipper merging is precisely defined in the Road Traffic Act. The main provisions relating to this driving method can be found in Art. 22 point 4 section 4a and 4b. In short:

• if you are driving on a multi-lane road and one lane is ending or is blocked, and the speed on the remaining lanes is significantly reduced, drivers in adjacent lanes must let in vehicles from the lane that is ending

• on a road with more than two lanes, if two of them are impassable, drivers in the third lane must let vehicles in alternately – first from the right, then from the left.

These rules were created to enable smooth traffic flow in difficult and unforeseen situations. They also prevent risky manoeuvres by drivers trying to enter a higher speed lane, e.g. when entering a motorway.

Zipper merging  – fines

Failure to zipper merge and not allow drivers to enter from the lane that is ending can have financial repercussions. The violation of zipper merging rules is treated as incorrect driving in road traffic and is subject to a fine of PLN 500. The amount of the fine may vary depending on the situation and place of violation, but it is usually several hundred zlotys. Follow these rules not only to ensure traffic flow and safety, but also to avoid unwanted fines.

The benefits of zipper merging

• effective traffic decongestion
• full use of available lanes
• driver peace of mind, eliminating cases of “squeezing in” between vehicles
• reduction of greenhouse gases emitted
• increased awareness among drivers about safe driving and road courtesy

Is zipper driving always mandatory?

No, there are certain situations when zipper merging is not required. Remember these rules:

• you do not have the right of way in a lane that is ending until you are at the end of it
• the turning lane is not treated as a lane that is ending
• zipper merging only applies to traffic jams, not to normal slowdowns

It is important that drivers are aware of these exceptions and follow them in practice, thus avoiding potential misunderstandings and accidents.

Summary: Is zipper merging mandatory?

• zipper merging is not only a form of road etiquette, from December 2019 it is also required by law in Poland 
• the main provisions regarding zipper merging can be found in Art. 22 point 4 section 4a and 4b of the Road Traffic Act 
• zipper merging involves the alternating entry of vehicles from lanes that are ending, thus resembling fastening a zipper 
• benefits of zipper merging include: effective traffic decongestion, full use of lanes and driver peace of mind 
• there are exceptions where zipper merging does not apply, such as no priority in a turning lane