Vactrax

From TLJwiki

A technology that links cities across the globe, the Vactrax network seems to be based on the 'vacuum railway' theory developed by Isambard Brunel in the nineteenth century. This uses air pressure, or vacuum, to drive trains at high speeds with little friction and therefore with great efficiency. Vactrax appears to be fast and inexpensive, though it is probably funded by corporations in Stark.

Zoe Castillo takes the Vactrax from Casablanca to Newport, so its network would appear to travel undersea as well.