A high tech alternative to the underground shamelessly inspired by Future Armada Argos III and Invictus.
Also know as Tube or T², this mass transportation system, manufactured by Ling Standard Product, is something of an hybrid between an underground and a lift.
The system is composed of spherical GravLev capsules moving in a 10' wide tube. Each capsule is voice controlled and can accommodate 11 sitting passengers (and about that much more standing ones during rush hours). The tube itself is equipped with automatic switching devices allowing every single capsule to reach every single stop of the network. Traffic is managed by a dedicated computer system handling the routing of capsules, call priorities, and restrictions (certain parts of the network may be made off-limits to some).
Main arteries of the network are made a bundle of three tubes allowing two-way circulation together with maintenance, emergency traffic and backup.
In communities where T² is installed, large private buildings often replace traditional lifts with a branch to the system, allowing commuters to take the tube nearly literally from their apartments to their offices.
Cargo capsules do exist and are used in communities with less or no other transportation system.
Designers also made provisions for the system to be used as escape capsules in large space stations or starships, the capsules being equiped with emmergency supllies and launch tubes being connected to the network. However, this later option has encountered little succes due to its higher price.