The Heysen Tunnels will be partially closed ovenight from 7pm Friday July 29 to 3am July 30.

Please expect delays while essential works are completed involving safety maintenance of electrical systems, including the ventilation, lighting, fire detection and emergency management systems.

During these works, Crafers bound traffic will be diverted into the Adelaide bound tunnel with lane (contra flow) and speed restrictions in place.

Please plan ahead and allow extra travel time.