Computers
All of the computers that run the subway ATCS today are 1990s-era computers that would be replaced by modern computers serving the same functions. These new computers are several generations ahead of the ones they replace and so the system would benefit from a quantum leap in computing power, data transmission rates and data storage capacity.
Telecommunication Technology
The current data communication network relies on coaxial cable and very short-range wireless communications over a lossy loop cable mounted between the rails. As part of the upgrade project, telecommunications will be upgraded to modern communication technologies such as fiber optic and Wi-Fi.
The new system software takes advantage of the greater capabilities of the computers and data transmission rates to offer more functionality, redundancy and speed.
On-street Junctions
On the street, rail junctions are controlled by independent interlocking control computers and track circuits detect the location of trains. As with the subway, these old computers would be replaced with modern zone controller computers that are connected to the rest of the system via the data communication network and the unreliable track circuits will be replaced with more reliable, modern technology.
Streetlights
Trains also interact with streetlights to get transit signal priority (TSP), but the existing TSP system relies on a fixed means of detection and performance has been disappointing along on-street Metro corridors like the T Third. Currently, a transmitter embedded in the roadway sends a signal to the traffic light ahead when it detects a train. This fixed setup does not adapt for changing roadway conditions or operating speeds, and if the train misses its window, it will wind up stuck at the traffic light for longer than if TSP were disabled.
Moden CBTC technology will do away with fixed detection. Instead, it will provide the TSP system with continuous updates on when a train is expected to arrive so the TSP can trigger adaptive streetlight cycles that will make trains more likely to get a green window, reducing travel times from traffic signal delays.