Buses are replacing trains on the Werribee and Williamstown Train Lines between Footscray and Newport, due to a damaged boom gate at the Hudsons Road level crossing in Spotswood.
Trains will continue to operate between Flinders Street and Footscray stations, and between Newport and Werribee and Williamstown stations, but delays are likely.
Metro Trains is asking passengers to check station platform displays, listen for announcements and allow extra time for their journey.
Motorists are asked to watch out for extra pedestrians and buses around train stations on the Werribee and Williamstown lines.
The VicRoads signals team is monitoring conditions in the area and will adjust traffic lights to assist with bus movements.
Details: traffic.vicroads.vic.gov.au or ptv.vic.gov.au