Zip merging in Switzerland: when to merge and who must let you in

What does zip merging mean?

Two lines of traffic become one by taking turns at a narrowing: one vehicle from the continuing lane, one from the lane that ends, then another from the continuing lane. The pattern resembles the teeth of a zip. It works when both lines approach predictably and drivers leave the necessary room.

Since 1 January 2021, this has been a legal duty in Switzerland, not simply a courtesy recommendation. VRV Article 8(5) requires alternating admission immediately before the narrowing where a lane ends or is blocked on a road with several lanes in the same direction.

You need to understand both roles. In the ending lane, continue to the merging point at a suitable speed and look for your turn. In the continuing lane, allow one vehicle to enter ahead of you in the alternating pattern, then follow in turn. That describes orderly cooperation; it is not a reason to create a conflict if someone makes a mistake.

The entering driver still has to change lane without endangering other traffic. Being entitled to cooperation does not authorise forcing another vehicle to brake or swerve into danger.

Using the ending lane is the intended approach

Drivers sometimes leave an ending lane hundreds of metres before roadworks, then regard vehicles using it further ahead as queue-jumping. For an ordinary lane reduction, using both available lanes up to the narrowing is the intended arrangement. The alternating merge takes place immediately before the lane can no longer continue.

Using the available road space avoids concentrating the whole queue in one lane prematurely and can shorten the tailback. Keep your speed appropriate to nearby traffic, the view and any workers or obstacles. This is not permission to rush past a slow queue at a large speed difference.

A hard shoulder is not an extra queuing lane unless it has officially been opened for traffic. Nor does zip merging permit crossing prohibited markings, ignoring a lane closure or driving through an obstruction to reach an imagined merging point.

A dangerous forced merge is still dangerous, wherever it happens. SVG Article 44(1) requires a lane change not to endanger other traffic. Use the legal space, indicate clearly and take turns at the actual narrowing.

Where does the rule apply?

The rule is not confined to motorways. It applies on roads with several lanes in the same direction when one lane ends or cannot be followed continuously:

When both lanes continue, there is no alternating entitlement to change lanes. Follow the normal keep-right and lane-use rules as applicable; the absence of a zip merge does not mean unrestricted lane choice.

How to merge, step by step

In the lane that ends:

1. Keep a predictable position: continue in your lane at a speed suitable for the queue and the visible narrowing.
2. Indicate in good time: communicate your intended lane change without implying that it is already safe.
3. Approach the merging point: use the available lane up to the narrowing, obeying closures, markings and any directions.
4. Take the next safe turn: merge into the space left ahead of the driver admitting you, behind the vehicle that has just taken its turn. Check the path and blind spot; do not force the gap.

In the continuing lane, leave enough room ahead and let the next vehicle from the ending lane enter in front of you. Follow it in turn; the next driver in your line admits the next vehicle. Predictable speed adjustment is more useful than an ambiguous gesture.

A brief gesture of thanks is optional, but attention and safe control come first. A gesture inviting someone in does not prove that every part of their path is clear.

If another driver refuses to cooperate, reduce your speed and stop if necessary. Wait for a safe opportunity; do not assume a gap is guaranteed within a particular number of seconds. Horn use, pressure or driving into the side of another vehicle cannot make the manoeuvre lawful.

Fixed penalties and their limits

The current Swiss Fixed Penalties Ordinance (OBV, Annex 1) lists these amounts for cases that qualify for the fixed-penalty procedure:

These amounts are not a price for creating a dangerous situation. If the conditions for the fixed-penalty procedure are not met, for example because of danger or an incident requiring further investigation, ordinary proceedings and additional consequences can follow.

A driver who deliberately closes a gap or accelerates to block an alternating merge may bear responsibility for a resulting collision. The entering driver also retains the duty to change lane safely. Responsibility depends on what actually happened, not simply on which lane ended.

The simplified procedure normally has no procedural costs and no criminal-register entry when settled under its rules. Rejecting it or failing to meet its conditions can lead to ordinary proceedings. For wider examples, see the traffic fines calculator.

Source: OBV Annex 1, items 306.4, 328.1 and 328.3.

Zip merging and the emergency corridor are separate duties

Both duties were introduced in their current form on 1 January 2021, but they solve different problems. Zip merging joins two traffic lines at a narrowing. An emergency corridor leaves access for emergency and assistance vehicles before they arrive.

On a motorway or expressway with at least two lanes in the same direction, form the corridor when traffic moves at walking pace or is stationary (VRV Article 36(7)). The leftmost lane moves towards the left; the lane immediately to its right and any further lanes keep towards the right. Leave the corridor between the leftmost lane and its neighbour.

Keep the hard shoulder clear unless an authorised traffic arrangement directs otherwise. The corridor is not a private overtaking lane, and drivers must not follow an emergency vehicle through it.

Before roadworks, both duties may apply together: form the emergency corridor in the queue, then merge alternately at the lane reduction. Watch the actual lane layout and any police or traffic-management instructions as the queue moves.