Right now the first phase of operable PTC will be from Bridgeport to New Haven, and Tarrytown to Croton. I was told this was strategically done as both divisions handle Amtrak and foreign freight RR's. And there is ongoing outside contractor work going on right now related to PTC.
Brief, fair-use quote:
Metro-North Will Not Meet Deadline for Safety Technology Installation
Despite receiving $1 billion in loans to do so, the commuter rail line has yet to install Positive Train Control in any of its locomotives.
Metro-North Commuter Railroad will not meet a year-end deadline to install technology that prevents trains from exceeding speed limits and helps avoid collisions, the Federal Railroad Administration (FRA) reported to Congress this week.
According to the report from the FRA, only 29 percent of commuter train lines are targeting to complete the installation of Positive Train Control (PTC) by the deadline. The national deadline was set in 2008, after a California passenger train derailed killing 25 people. The accident prompted Congress to pass the Rail Safety Improvement Act, which required both commuter and freight lines around the country to install the technology by the end of 2015.
...
In April, the Federal Railroad Administration granted the MTA almost $1 billion in loans to help implement the technology on Metro-North and Long Island Railroad trains. Despite the financial assistance, the FRA reports that none of the 681 Metro-North locomotives intended for the equipment have received it.