NEW YORK (AP) – A plan to computerize the subway signal system on all train lines could take 35 to 40 years to complete, said New York City Transit officials.

The agency has spent $288 million on the computerization project since awarding the contract in 1999.

The system will make its debut in July on the L train and will eventually replace the electromechanical switches throughout the entire subway system that have been used for a century.

The agency has proposed using the new system, called communication-based train control, on the 7 train and part of the F train by 2009.

Computerizing the rest of the lines could take until 2045, said Michael Lombardi, senior vice president for subways, during a City Council Transportation Committee meeting, according to Friday’s edition of the New York Times.

The vulnerability of the older system was highlighted after a fire last month destroyed a signal relay room at the Chambers Street station in Manhattan, shutting down service on the A and C trains.

The damage inconvenienced thousands of commuters, but Lombardi said the signal room was a relatively unimportant piece of the subway’s network.

“There are relay rooms throughout the system that are much more critical,” Lombardi said

While working toward computerization, Lombardi said the agency is modernizing the current system.

Since 1982, $2.4 billion has been spent to bring 75 percent of the signaling system to a state of “good repair.” The rest will be improved by 2020, Lombardi said.

Since 1960, 185 of the 198 signal relay rooms have been modernized. Thirteen others, including the Chamber Street room, will be upgraded by 2009.