That's not true. The L line is by far the most advanced line in the system because of the reasons you said. When I lived in Williamsburg, I remember coping wi

That's not true. The L line is by far the most advanced line in the system because of the reasons you said. When I lived in Williamsburg, I remember coping with weekend shutdowns all the time for upgrades. But the L now is (I believe) only one of 2 lines with modern signaling and CBTC (computer based train control), it was the first to have countdown clocks, and it runs with the least gap time (headway spacing) of any trains in the system. That being said, it still is extremely overcrowded because of waterfront highrise development and the general shift to Brooklyn. This is why you're starting to see conversations about extending platforms (which for the underground stations is incredibly expensive). And yes, I'm aware of the Sandy tunnel remediation work shutting it down for a year or so. Still, the L is already upgraded (so is the 7 which also doesn't share much track). It's getting CBTC on the other lines with modern signaling that will be the hard jobs because of shared track.