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

You are correct: serious or deadly injuries can already occur in a collision at speeds as low as 30 km/h if no safety belt is worn. Without a seatbelt, even a relatively low-speed crash can cause the body to be thrown forward with great force, leading to life-threatening injuries. That is why it is crucial to always wear a safety belt, no matter how short the trip or the speed involved. This rule emphasizes that safety belts are effective in preventing severe injuries even at low speeds, and underscores their legal requirement in Germany.