Eight kilometres of single track from Dandenong to Cranbourne will be duplicated as part of the Cranbourne Line Upgrade.
This will remove the bottlenecks that cause delays and allow the number of train services to double during peak times, delivering trains every ten minutes along the whole Cranbourne line.
Tracks will also be upgraded around Caulfield station, where the Frankston line splits off from the Cranbourne-Pakenham line, and around Dandenong Station where the Cranbourne and Pakenham lines separate.
This will help move trains more quickly through these stations, cutting delays and getting people home sooner.
The project will create more than 1000 jobs. Detailed planning and procurement will start in 2019, with construction to start in 2021 and finish by 2023.