At which impact speed must you reckon with serious or deadly injuries when no safety belt is worn?

In German traffic safety rules, wearing a seatbelt is crucial because it significantly reduces the risk of serious or fatal injuries in a collision. Without a safety belt, even at relatively low speeds—starting from about 30 km/h—there is a high chance of severe injury or death in an accident. This is because at 30 km/h, the force of impact is already strong enough to cause the occupant to be thrown against the interior of the vehicle or ejected, which is often deadly. Therefore, the rule highlights the importance of fastening seat belts at all times, as serious injuries can occur from impacts at much lower speeds than people might expect.