Joining a motorway: accelerate, observe and merge safely
In normal flowing traffic, vehicles already on the motorway have priority. Use the acceleration lane to adjust your speed, observe the traffic, indicate and check the blind spot before merging into a sufficient gap. Avoid an unnecessary stop, but never force your way in. In slow-moving traffic, the zip-merging rule applies (VRV Article 36(4)).
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Who has priority at the entrance?
In normal flowing traffic, the answer is clear: traffic already on the motorway has priority (VRV Article 36(4)). An entry lane does not give you the right to push between two vehicles. The driver on the through lane should cooperate where safe, but you must choose a suitable gap and merge without endangering others.
There is an important exception for slow-moving traffic: the law expressly applies the zip-merging rule at motorway entrances. Vehicles on the through lane must allow vehicles from the entry lane to merge alternately. Even then, an entering driver may not force a dangerous lane change.
The green motorway sign (4.01) marks the special motorway rules; an expressway uses sign 4.02. In general, only motor vehicles capable of and permitted to reach at least 80 km/h may use these roads. This is an admission requirement, not an obligation to drive at least 80 in every situation. The law has specific exceptions for certain authorised or road-service vehicles. Pedestrians and ordinary bicycles cannot use a motorway.
Keep the distinction in mind when answering a theory question: first decide whether traffic is flowing or slow-moving, then apply the matching priority and merging rule.
Use the acceleration lane to match the situation
The acceleration lane gives you room to adjust your speed and select a gap. Use the available lane while observing the motorway early; do not merge prematurely simply because the first dashed marking has appeared. The aim is a speed appropriate to the traffic you will join, always within the applicable limit and suitable for the road, visibility and vehicle.
A large speed difference makes merging harder. For example, at a constant 120 km/h a car covers about 33 metres per second, while at 80 km/h it covers about 22 metres. If one vehicle is closing on another at that 40 km/h difference, a 100-metre separation disappears in about nine seconds. Real traffic speeds can change, so this is an illustration rather than a gap-selection formula.
Matching speeds does not make an inadequate gap safe. You still need enough space ahead and behind to merge without endangering anyone, followed by a sufficient following distance. Do not treat “small speed difference” as permission to squeeze into a small gap.
On an acceleration lane, passing on the right is permitted only up to the end of the continuous line, including a double line with the continuous line on the left (VRV Article 36(5)(c)). Respect the markings: that permission does not allow crossing the continuous line or using the hard shoulder. Beyond that point, assess the applicable traffic rules rather than assuming that every right-side pass remains permitted.
A safe sequence for joining
- Observe early: assess the traffic, its speed, available gaps and the length of the acceleration lane. Signal your intended merge in good time without misleading others.
- Adjust your speed: accelerate appropriately within the limit and conditions. There is no universal target such as “always above 80 km/h”.
- Check the intended path: use mirrors and an appropriate blind-spot check. The exact observation method depends on your vehicle and visibility; an assistance warning is not a substitute for checking.
- Select the gap: adjust smoothly to fit behind or ahead of the relevant vehicle, keeping adequate room for both. Slowing may be necessary if the gap changes.
- Merge when safe and permitted: cross only permissible markings, move gradually into the through lane and cancel your indicator once the manoeuvre is complete.
- Settle into a safe following distance: check the traffic around you again. The “half the speedometer in metres” aid is not a guarantee that the legal distance requirement is met.
The steps describe one connected observation and driving task. A fixed mirror–signal routine is not enough if traffic changes while you accelerate. Keep reassessing until the lane change is complete.
At a slow-moving queue, use the entry lane to the merging point and cooperate with alternating vehicles. See zip merging for the queue-specific sequence.
What if there is no safe gap?
Avoid stopping unnecessarily on the acceleration lane: starting from rest leaves you with a larger speed difference and less room to accelerate. Plan early, observe several vehicles and adjust your speed to a suitable gap while you still have space.
If no safe merge is possible, do not force the manoeuvre. Slow and, if unavoidable, stop safely before the lane ends. Do not blindly drive to its very tip just to preserve a “never stop” rule. Restart only when a sufficiently large gap allows you to accelerate and join safely; a gap suitable for a moving car may be far too small for a stationary one.
The hard shoulder is normally for emergencies, not an extension of an acceleration lane or a way past a queue. Unauthorised driving on it can attract a CHF 140 fixed penalty; additional danger or another offence can lead to ordinary proceedings. Where a hard shoulder has officially been opened as a running lane, follow the displayed lane-control instructions.
Never reverse or make a U-turn because you missed a gap or an exit. Continue by a lawful, safe route. In a genuine breakdown, apply the motorway emergency procedures rather than treating it as an ordinary failed merge.
Five mistakes to recognise
| Mistake | Why it matters and what to do |
|---|---|
| Joining substantially slower than freely moving traffic | The speed difference can close gaps quickly. Use the acceleration lane to adjust speed within the conditions and limit. |
| Stopping without necessity | A restart needs a much larger usable gap. Plan early, but stop if safety genuinely requires it. |
| Relying on a mirror or assistance system alone | A vehicle may be in an area not covered by that view. Check the intended path and relevant blind spot. |
| Crossing a continuous line | The lane may only be entered where the markings permit it. |
| Moving straight across into a second motorway lane | Each lane change needs its own safe opportunity and observation. Join the adjacent lane first and reassess before any further move. |
These are useful learning situations, not a ranking drawn from recorded test failures. Explain the danger in each case rather than memorising only a label. The speed-limit lesson and stopping-distance lesson help with the underlying judgement.
If you are already on the motorway
Keep watching entrances as part of your observation ahead. In normal flowing traffic, an entering vehicle does not automatically oblige you to brake or move left, but having priority never justifies creating an avoidable danger. A modest, predictable adjustment may help when it can be made safely.
Before moving left, check that the lane change itself is safe and permitted. Do not move into an occupied lane or brake abruptly merely to create a gap. An entering driver's indicator communicates an intention, not proof that the path is clear.
In slow-moving traffic, alternating admission at the merge is a duty. Leave enough space to let one vehicle merge ahead of you in turn. Deliberately closing the gap defeats that rule. The entering driver must still observe and merge without forcing a collision risk.
After joining or admitting another vehicle, restore an adequate following distance. Cooperation should make everyone's movements easier to anticipate.
Related signals
Common theory-test traps
- At a motorway entrance in normal flowing traffic, vehicles already on the through carriageway have priority.
- In slow-moving traffic, zip merging applies at the entrance. It still does not authorise a forced or dangerous lane change.
- Use the acceleration lane to adjust speed; there is no universal minimum joining speed for every situation.
- Avoid an unnecessary stop, but stop safely if no safe merge is possible. The hard shoulder is not an ordinary continuation of the acceleration lane.
- An indicator does not confer priority. Check the path and blind spot, obey the markings and maintain enough space ahead and behind.
Distinctions
- Zip merging applies at motorway entrances when traffic is slow-moving; normal flowing entry has a different priority rule.
- The motorway maximum is generally 120 km/h for an ordinary car in favourable conditions, but signs and vehicle limits can reduce it. See Swiss speed limits.
- The space you need after merging depends on recognition and braking as well as speed. Read about stopping distance.
Common questions
Who has priority when I join a Swiss motorway?
In normal flowing traffic, vehicles on the through carriageway have priority. In slow-moving traffic, the alternating zip-merging rule applies. In either situation, do not force a dangerous lane change.
How fast should I drive on the acceleration lane?
Adjust towards the speed of the traffic you will join, within the speed limit and the conditions. There is no single correct speed for every entry. Use the available lane and choose a sufficient gap.
May I stop if I cannot merge?
Yes, if it is unavoidable for safety. Avoid an unnecessary stop through early observation and speed adjustment, but never force your way in. A restart requires a sufficiently large gap and room to accelerate.
May I continue onto the hard shoulder?
Normally no: the hard shoulder is for emergencies, not extra merging space. Follow an official opening of the shoulder as a running lane where one exists. Unauthorised shoulder driving can attract a CHF 140 fixed penalty.
Must a driver already on the motorway move left for me?
There is no automatic duty to change lane at an ordinary flowing entrance. That driver must still avoid endangering others. In slow-moving traffic, drivers must allow alternating merging, while checking that their own actions are safe.
General practice quiz covering different topics · no registration required