What is the maximum speed you are allowed to drive a truck with a permissible total mass of 40 t on autobahns?

For trucks with a permissible total mass over 3.5 tons, including those weighing up to 40 tons, the maximum permitted speed on German autobahns is 80 km/h. This is set by law to enhance safety, as heavy vehicles require longer braking distances and are more difficult to control at higher speeds. Therefore, 80 km/h is the correct and legal maximum speed, unless special permission or a sign indicates otherwise. Remembering this specific limit will help you answer similar questions about speed limits for heavy vehicles on highways in the future.