The price tag on an ambitious signal improvement on the PATH rail system linking New York and New Jersey is poised to rise, even as the system prepares to shut down its link to lower Manhattan for 45 weekends over the coming year.

The rising cost is being driven in part by a decision reached in December, shortly after a fatal Metro-North train crash in the Bronx, to ensure that the 21-mile PATH train system complies with a federal mandate to install anti-collision systems by the end of 2015.

The system, known as positive train control, will be installed across the PATH system over the next two years, PATH officials said. The rail network will also continue the development of a more elaborate signal system to provide protection against crashes while allowing the railroad to run more trains per hour, improving efficiency.

The shutdowns—between the Exchange Place station in Jersey City and the World Trade Center—are scheduled to begin Feb. 14 and continue on most weekends during 2014.

The shutdown of the transit line comes just months before the expected May opening of the 9/11 Memorial Museum. One World Trade Center is expected to open in 2015.