Map of Future Indonesia: Java — Bali
Around 56% of Indonesia’s population are concentrated in the island of Java, so it come as no surprise that the rail infrastructure were mostly developed here among all islands. Anyer-Banyuwangi has been connected by railroad since 1920s, built by the Dutch Colonial (There were even plans to build railroads in Kalimantan & Sulawesi, but scrapped out of the Great Depression)
This map were created mostly based on the existing railroad, as well as the now-defunct routes, like the Madura Line, with little modification (such as connecting Bayah of southern Banten with Sukabumi)
One major addition is the railroad in Bali. Government have long planned to build multiple train routes on the Island of Paradise. Here I took three routes and connecting one with Java (Using train from Jakarta all the way to Bali sounds like fun!)
Many of the defunct routes were built for transporting goods no longer massively produced, like coal in Bayah, or sugar in Paiton. But with doubling interconnected population nowadays, the train routes in Java would do just fine if being reactivated.