Coaches are replacing trains on the Geelong Line between Geelong and Lara, due to a track fault in the North Shore area.
Coach services are already in operation between Waurn Ponds and Geelong, due to ongoing upgrade works.
Passengers are being asked to check station platform displays, listen for announcements, and allow extra time for their journey.
Geelong Line trains will continue to operate between Southern Cross and Lara.
Motorists are asked to be vigilant for extra pedestrians and coaches around train stations along the line.
Services will resume when repairs have been completed.
Real-time traffic conditions are available at traffic.transport.vic.gov.au. The latest public transport information and network status is available at ptv.vic.gov.au or in the PTV mobile app.
