Saturday night, for two hours, a catastrophic signal failure suspended all PATH services severing connections between Jersey City and New York. Around nine o’clock, the last train for two hours limped into the Grove Street station a few feet at a time while nervous New Yorkers looked on in horror. For two hours, the Hudson River might as well have been the Berlin Wall.

Many Jersey City bound passengers stuck in New York were sent on a circuitous route on NJ Transit trains, requiring a transfer at Secaucus Junction to Hoboken bound trains before a second transfer to the light rail. Ferry services were not operating.

The signal failure may bolster Mayor Healy’s argument in favor of building a Jersey City light rail connection to Secaucus Junction via Sixth Street and the Bergen Arches; such an alternative route would have reduced the total number of transfers required to circumvent PATH services and would have put Journal Square within walking distance of a train line. Still, if such a failure was to occur during a rush hour, the thousands of daily passengers would likely crush alternative services.

The PATH recently celebrated a 100 year anniversary, and the need for modernizing the system is obvious. The Port Authority last year promised to upgrade the PATH signals with a modern system that would allow a 20% increase in peak period trains, but that project will require 7 years to complete.

But even modern systems are not without flaws. For instance, the MTA began upgrading the L lines signals more than a decade ago, and while the line is now perhaps the most efficient in New York’s system, the initial launch was not without hiccups, and peak efficiency is still two years away. Another signal fiasco in 2005 threatened to disrupt A C service for years after a fire destroyed signal equipment; that problem was later resolved within months, not years.

Yet while disruptions in MTA trains are inconvenient, the system continues to function. Not so with the PATH as Saturday’s signal problems went on to shut down the entire system. Its certainly not a premature notion to suggest the time has come for a new, separate subway line connecting Manhattan and New Jersey. After all, the Second Avenue subway line was first proposed in 1929, and that may not be completed for another twenty years. Not only are thousands of new residences being constructed in Jersey City, but new developments adjacent to the Harrison PATH station will be dependent on the service. Newark’s revitalization too will add commuters, as well as proposals in Bayonne, connected to the PATH by the light rail.

Saturday’s service disruption was rather benign in contrast to what could have happened at rush hour on a weekday, but it should still serve to remind riders and the Port Authority alike just how vulnerable the system is, and the need for redundancies.