Under German civil law, liability for personal injury is primarily governed by § 823(1) of the German Civil Code (Bürgerliches Gesetzbuch, BGB). This provision establishes negligence-based liability: anyone who unlawfully injures the life, body, health, or property of another is obliged to compensate for the resulting damage. The scope of this liability is shaped by the concept of “traffic safety obligations” (Verkehrssicherungspflichten), a judge-made legal doctrine requiring any person who creates a source of danger to take reasonable measures to prevent foreseeable harm to third parties.

The duty applies whenever an individual introduces an obstacle or risk into an area habitually used by others. German courts consistently hold that such risks must either be eliminated, reduced, or clearly communicated through adequate warnings. The standard is objective: a person is liable if they fail to take the precautions that a prudent and responsible individual would have taken in the same situation (§ 276 BGB).

Within this framework, liability does not depend on whether the activity is commercial, recreational, voluntary, or private. What matters is whether a foreseeable risk was created and whether reasonable safety measures were taken. Hidden or unexpected hazards, particularly those not easily detectable by ordinary users of public spaces, are considered violations of traffic safety obligations because they expose others to preventable danger.

Contributory negligence by the injured party (§ 254 BGB) may reduce liability, but only where the injured person failed to exercise the level of care expected for their own safety. However, contributory negligence does not eliminate liability when the primary cause of harm stems from a hazard that the defendant knowingly or negligently introduced into the environment.

In the present case, the Court applied these principles to a slackline installed in a public park. Because the slackline was stretched at a low height and was not visible from a reasonable distance, it created an unexpected obstacle for other park users. The installer therefore bore the burden of ensuring adequate visibility or warning of the hazard. The absence of such precautions constituted a breach of traffic safety obligations and led to liability under § 823 BGB

Finally, due to the uncertain long-term effects of the injuries, the Court issued a declaratory judgment confirming liability for future damages which is a common measure in German tort law when future consequences cannot yet be quantified.

§ 823(1) BGB* – General civil liability for unlawful injury to life, body, health, freedom, property.
§ 823(2) BGB – Civil liability arising from violation of a statute intended to protect others.
§ 32 StVO** – Prohibition against placing or leaving objects on public roads where they can endanger traffic (“traffic obstruction”).
§ 315b StGB*** – Criminal offence of dangerous interference with road traffic (includes creating hazardous obstacles).

*Bürgerliches Gesetzbuch: German Civil Code

**Straßenverkehrsordnung: German Road Traffic Regulations

***Strafgesetzbuch: German Criminal Code

The events took place in a public park in Karlsruhe, where the defendant had installed a slackline between two trees at approximately knee height. The slackline was positioned across a grassy area adjacent to a path routinely used by pedestrians and cyclists. Due to the angle of approach and the color and height of the line, it was not visible to users of the path until they were very close to it.

A cyclist entered the park and followed the shared path in normal daylight conditions. As she approached the grassy area, she did not perceive the slackline and collided with it, being thrown from her bicycle and sustaining injuries. Emergency services were called, and she later sought compensation for medical expenses, pain and suffering, and material losses.

The injured cyclist (claimant) brought a civil action against the person who had installed the slackline (defendandt), alleging that it constituted a hidden and unexpected obstacle in an area open to public use. The defendant argued that slacklining was a common recreational activity in parks and that the cyclist should have been attentive to her surroundings.

In first instance, the court ruled in favor of the cyclist, finding that the slackline installer had breached their traffic safety obligations by creating a foreseeable hazard without implementing any warning measures. The defendant appealed the decision to the Higher Regional Court of Karlsruhe (Oberlandesgericht Karlsruhe), which upheld the lower court’s findings and confirmed liability.

Defendant’s Arguments:
The slackline installer appealed the first-instance judgment and structured his arguments around several key points:

• No breach of traffic safety obligations
He argued that the lower court had misapplied the doctrine of Verkehrssicherungspflicht. According to him, installing a slackline in a public park is a common recreational practice and does not automatically constitute a hazardous activity requiring special safety measures.

• Sufficient visibility and foreseeability
The defendant contended that the slackline was adequately visible to park users and that the cyclist should have perceived it in time to avoid the collision. He maintained that the accident resulted from the cyclist’s lack of attention rather than from an objectively hidden obstacle.

• Absence of a duty to warn
He argued that there is no general legal requirement to place signs or warnings around temporary recreational equipment installed in open, grassy areas of a park, and that the court improperly imposed overly strict safety expectations.

• Contributory negligence by the cyclist
The defendant submitted that the cyclist’s own inattentiveness constituted contributory negligence under § 254 BGB and should significantly reduce or eliminate his liability.

 
Claimant´s Arguments 
The injured cyclist defended the judgment of the first instance and presented the following key arguments:

• Existence of a hidden and unexpected obstacle
She maintained that the slackline was not visible from a reasonable distance due to its height, angle, and color, and therefore constituted a hidden danger for park users. As such, the installer was required to ensure adequate safety measures.

• Clear breach of traffic safety obligations
She argued that the defendant created a foreseeable source of danger in an area frequented daily by pedestrians and cyclists. Under established case law, anyone introducing an obstacle into public space must ensure that third parties are not exposed to avoidable hazards.

• No contributory negligence
She rejected the allegation of contributory negligence, stating that she was cycling normally and could not have anticipated a slackline at knee height extending across the area adjacent to the path.

The Higher Regional Court of Karlsruhe based its judgment on the German doctrine of traffic safety obligations (Verkehrssicherungspflichten). The Court held that anyone who introduces a potential hazard into a public space must take reasonable precautions to prevent foreseeable harm. This duty applies irrespective of whether the activity is recreational or non-commercial.

Relying on expert evidence, the Court found that the slackline, set at knee height and difficult to detect from a distance, constituted a hidden and unexpected obstacle for users of the park’s shared path. Because the installer failed to take basic precautionary measures—such as ensuring sufficient visibility or providing warnings—the Court concluded that he breached his duty of care under § 823(1) BGB.

The Court rejected the defendant’s arguments that slacklining is a common practice not requiring safety measures and that the cyclist should have been more attentive. It held that the cyclist could not reasonably anticipate such an obstacle and that no contributory negligence applied. The appellate court therefore confirmed the first-instance judgment and upheld the defendant’s liability.

This judgment clearly illustrates how general traffic safety rules apply when recreational activities take place in public spaces. The Court confirmed that a slackline stretched across a shared-use path constitutes a traffic obstruction and that users must ensure their equipment does not create hidden hazards for others.

A significant aspect of the decision is the emphasis on visibility and avoidability. Expert reconstruction showed that the slackline was practically undetectable until very close, which led the Court to reject any contributory negligence. The case highlights the value of technical evidence when assessing the foreseeability of an obstacle.

From a practical standpoint, the ruling clarifies that leaving a slackline unmarked and unattended in a public area can amount to gross negligence, even if the activity itself is low-risk. It reinforces that outdoor users must consider their impact on all other users of a shared environment.

LAC notes that the reasoning aligns with other cases in the database involving unexpected obstacles or unsafe setups in shared spaces, underscoring the importance of adequate marking, supervision, and hazard awareness in recreational settings.