What is the mandatory time interval for performing the vehicle roadworthiness test for coaches and buses?

In Germany, coaches and buses must undergo a roadworthiness test (Hauptuntersuchung) every 12 months. This annual inspection ensures the vehicle meets safety and environmental standards, helping to prevent accidents and maintain road safety. The regular 12-month interval is stricter than for many other vehicles, reflecting the increased responsibility due to the number of passengers carried. Remembering this 12-month rule will help you correctly answer similar questions about vehicle inspections for passenger transport vehicles.