The Canarsie Line is one of only two New York City non-shuttle subway lines that hosts only a single service and does not share operating trackage with any other line or service; the other is the IRT Flushing Line, carrying the . Because of this, it was chosen as the location of the first fully automated line of the New York City Subway. The automation project was among the first in the world to use a radio frequency-based system. The plans for installation were laid out between 1999 and 2002. Communications-based train control (CBTC) was installed in pieces between 2003 and January 2006: the elevated section of the line south of Broadway Junction was completed first, followed by the underground section north of Broadway Junction. The project cost $340 million, with $78 million of it used to upgrade track interlockings on the line.