- the San Joaquins, who will share CAHSR's track and effectively be California's NE Regional equivalent train, will electrify as soon as the legislature allows. Right now Sacramento doesn't want to put wires up until there is a continuous path from San Jose to Merced
- Metrolink will have to electrify some operations in order to work with CAHSR between Palmdale and Anahiem
- the Surfliner will pressure UP to allow it, which stands a chance of actually happening given how the Surfliner serves Ventura Co (home of President Reagan) and San Clemente (home of President Nixon) so they have pull within the Republican party, and vice versa this is how Republicans from the area would negotiate a transit tax
- SMART, especially when they already own all the track. But this would require a new tax, and voters rejected it in 2018 (similar to how voters rejected a Caltrain tax in 1986). Regardless it's at least on the table.
- the Capitol Corridor, if they can figure out UP. The proposed reconstruction of the Sacramento Northern route as a freight bypass and a downtown Oakland subway exist for this purpose, it's how UP would be coaxed into allowing some under-wire operations in their territory between Martinez and Emeryville. UP could also sell the former SP subdivision in the way they sold/are selling SP's Altamont route
- ACE, depending on how things shake out with what is now Valley Rail, if VR goes well then they'll just drop in two more tracks and fuck over the freeway users
- Coaster, which will have to electrify all of their operations for CAHSR part 2
All of this is made plausible by Prop 1A and CAHSR itself. This is why it's such a massive deal because it touches upon every large city in the state and, except for SMART, every rail agency.
Outside of CA Denver already has a partially electrified system that will expand, and Utah is where Stadler wants to sell electrification as it's where Caltrain's new electric units are being made.