Trains are really cool! I grew up in Taiwan and now live in the San Francisco Bay Area, so I drew some future train maps of both places.
Most rail systems in the world have a distance of 1435 mm (4'8.5") between tracks, a distance known as "standard gauge". Both Taiwan and the Bay Area have anomalies as explained below.
Taiwan is one of the few places in the world where the distance between conventional train tracks is 1067 mm (3'6"). Conventional (non-metro) trains in Taiwan also run on the left instead of the right.
Both of these are legacies of fifty years of Japanese colonial rule from 1895 to the end of World War II in 1945. Taiwan still buys trains from Japan to this day.
Most of the metro lines are human-operated. The only autonomous train systems are the the Wenhu Line (light-brown, center-right) and the Circular Line (yellow).
I wonder if all train lines can be autonomous one day. I think it would be very cool to be the one to build systems that can retrofit any train line to make it run autonomously.
Keelung and Cape Santiago
The San Francisco Bay Area includes conventional heavy rail, high-capacity metro, and light rail. The future California High Speed Rail is shown in yellow-orange running from the city to Gilroy.
BART was built with unconventional standards, making maintenance difficult. The newest train cars had to be custom-built by Bombardier.
The most prominent feature of BART is the transbay tube that connects San Francisco and the East Bay. Four of the five lines travel through this tube, which makes it very congested during rush hours. There are plans for a second tube, but no one knows when it's going to be built.
The newest member of the map below is the Sonoma-Marin Area Rail Transit (green, northwest) that runs from Larkspur to Sonoma County airport. It's only one train line so far, but I imagine SMART could go to Oakland one day via a new bridge.
The Dumbarton rail corridor (teal, crossing the south bay) connects Redwood City and Hayward but hasn't been operational for over 80 years.The line passes Facebook's Menlo Park HQ within walking distance, and Facebook agreed to take part in the line's re-construction in 2019. With the pandemic ushering remote-work, Facebook changed its mind.
The Caltrain travels from San Francisco to San Jose through the city centers of Silicon Valley. Originally owned by Union Pacific and operated with diesel trains, Caltrain will be electrified in 2022 with trains from Stadler.
The only autonomous train line is the automated-guideway transit line between Coliseum station (BART) and Oakland International Airport (gray, center of map).