Changing lanes: who is liable in the event of an accident?
Lane changes are a common cause of accidents on the road. But what rules should be observed in this situation and what principles apply to liability in the event of an accident when changing lanes?

Anyone who changes from one lane to another with their vehicle must proceed with particular care so as not to endanger other road users. Mistakes are regularly made in this regard, making lane changes a frequent cause of accidents on the road. But what rules must be observed and what principles apply to liability in the event of an accident when changing lanes?
1. Rules for changing lanes
Changing lanes is a traffic situation that is not without danger and requires special attention on the part of the driver. This is why changing lanes is also expressly regulated in the road traffic regulations.
§ 7 para. 5 StVO stipulates in this regard: “In all cases, a lane may only be changed if there is no danger to other road users. Any change of lane must be announced clearly and in good time; the direction indicators must be used when doing this.”
Extreme care must be exercised: The lane change may only take place if the traffic situation permits it and the danger to other road users is excluded.
Therefore, the following four steps should always be followed when changing lanes:
- Check the traffic situation in good time before changing lanes using the inside and outside mirrors
- If there is an opportunity for a lane change, put your turn signal on first to indicate your intention to turn
- Check again by looking in the mirror and looking over your shoulder whether the lane is clear for the lane change
- If the lane is free, the lane change can take place.
2. Liability for traffic accident when changing lanes
It is not uncommon for drivers to disregard the increased care required for changing lanes and to try to force the lane change, resulting in accidents when changing lanes.
In principle, in the event of a rear-end collision when changing lanes, the person who changed lanes is liable. That’s because a special rule of evidence, known as prima facie evidence, applies to lane changes. This is an evidentiary relief developed by case law in tort cases. Then the presumption applies that the person who changed lanes caused the accident. However, the prima facie evidence does not apply if the lane changer can prove a different course of the accident, z. B. through witness statements.
In the case of a rear-end collision, this principle of prima facie evidence initially applies to the detriment of the person rear-ended: In the case of rear-end collisions, the first prima facie evidence is that the rear-end collision was the culpable cause of the accident.
Several causes can be considered for this:
- Lack of safe distance
- Inattention
- Inappropriate speed.
This principle often leads to the sole liability of the person who rear-ended the vehicle. This is because vehicle drivers are obliged to adjust their driving in such a way that they can stop in good time if necessary if an obstacle appears on the roadway.
The evidence situation in such a rear-end collision is to be judged differently if a lane change is added as a further circumstance:
In this case, the prima facie evidence applies to the detriment of the lane changer: If it is certain and proven that a rear-end collision occurred in close temporal and local connection with a lane change by the driver in front, the prima facie evidence speaking against a rear-end driver recedes. In this case, the person who changed lanes is usually liable, not the person who rear-ended the vehicle. Partial fault of the rear-end driver is then still conceivable. For example, if he accelerated suddenly and this was not foreseeable for the lane changer. However, the lane changer must prove these circumstances and thus invalidate the prima facie evidence.
It is not so easy to disprove the prima facie evidence. While it is not necessary to prove a concrete fact. However, assertions in the dark are of no help; circumstances must be proven that give rise to the serious possibility of a different set of facts than the typical one. This is possible z.B. Through clear testimony.
3. Special case of zipper procedure
If an accident occurs during a lane change in a zipper situation, the question regularly arises in legal disputes as to whether liability should be assessed differently in this case.
The zipper procedure is a special regulation of the road traffic regulations for the lane change at lane narrowings.
It is contained in § 7 para. 4 StVO regulated: “If on roads with several lanes for one direction the continuous use of a lane is not possible or a lane ends, the vehicles prevented from continuing to drive must be enabled to cross over to the adjacent lane in such a way that immediately before the beginning of the narrowing these vehicles can each take turns to move into position after a vehicle driving on the continuous lane (zipper procedure).”
From this it follows that the one, which on the passable roadway and/or. Driving in the target lane, must allow motorists to merge from the ending lane. As with a zipper this is to take place in the alternation, so that in each case a lane changer is made possible, then again one on the target lane drives etc.
In the event of a collision between a vehicle changing lanes and a vehicle traveling in the target lane, the question of liability has been assessed in several court decisions.
Most recently, the Munich Higher Regional Court had to rule on this issue. The driver of a Porsche changed lanes on a highway in a zipper and braked to a stop after changing lanes, causing the following truck to hit the rear of the car.
First of all, the Munich Higher Regional Court (ruling of 21.4.2017, 10 U 4565/16) on the fact that the principles of prima facie evidence also apply in the event of an accident in connection with a zipper procedure. The proof of the first appearance speaks therefore also with an accident in the zipper procedure for a sole adhesion of the one, which accomplished the lane change. This was prima facie evidence against the Porsche driver as a lane changer.
The OLG Munich continued:
- The other party may be held jointly liable in such an accident scenario if the other party should have seen the danger of a collision approaching and could have reacted in such a way as to prevent the accident.
- However, the burden of proof lies with the lane changer, there is no automatic joint liability.
However, the prima facie evidence against the Porsche driver as the lane changer could not be shaken in these proceedings, so that sole liability remained.
Practice note: Particularly in connection with a lane change in the zipper procedure, some accident scenarios are conceivable in which the rear-end collision is the sole fault or contributory negligence, for example due to inattention or lack of safety distance in the area of the lane narrowing. Nevertheless, it should be noted that even in these cases, the lane changer is generally considered to have caused the accident, and he bears the burden of proof for invalidating this prima facie evidence.
4. Rear-end collision with claimed lane change
Another case of a rear-end collision on a highway had to be decided by the Federal Court of Justice (BGH, judgment of 13.12.2016 – VI ZR 32/16). As in the aforementioned case, a rear-end collision occurred on the highway. However, it remained disputed in detail how the accident occurred. The plaintiff claimed the defendant made a jerky change from the passing lane to the right lane, making the rear-end collision unavoidable to her. On the other hand, the defendant denied having changed lanes.
If, in such a constellation, the rear-end driver cannot prove that the preceding driver changed lanes, the prima facie evidence explained at the beginning is again decisive to the detriment of the rear-end driver: The only undisputed fact remaining is the rear-end collision, which is typically based on the fault of the rear-end driver. The driver in front does not have to prove that a lane change did not take place; his denial is sufficient. If the rear-end collision victim cannot prove that the preceding vehicle changed lanes, the BGH rules that the rear-end collision victim is solely at fault and therefore fully liable.
5. Conclusion
- When changing lanes, the special duty of care according to § 7 para. applies. 5 StVO. Who disregards these, is liable in case of an accident regularly alone.
- Because in a rear-end collision involving a lane change, prima facie evidence supports the conclusion that the lane changer was at fault in causing the accident.
- The lane changer can only invalidate the prima facie evidence by proving the fault or contributory negligence of the other party involved in the accident.
- In the case of an accident in which the lane changer is only alleged to have changed lanes, on the other hand, the burden of proving that the lane changer was (partly) at fault lies with the person who rear-ended the vehicle.