Guarda su Altadefinizione. On November 25, 1973, the first of four car-free Sundays transformed West Germany's deserted highways into spaces for walking, cycling, and horse-drawn carriages, while towns and cities took on a festive atmosphere. Introduced during the oil crisis to conserve fuel after the Arab oil embargo and production cuts following the Yom Kippur War, the measure became an unforgettable collective experience. Beyond the immediate energy shortage, the crisis marked a turning point, ending the postwar economic boom and encouraging greater awareness of energy use, consumerism, and environmental issues.