chose to keep paying a stable dividend rather than reinvest in infrastructure. The result was dilapidated stations, slow, disjointed track conditions, and antiquated rolling stock which frequently broke down. In 1968, the PRR merged with the New York Central to become Penn Central, which declared bankruptcy in 1970. In 1976, Amtrak took ownership of the line between Philadelphia and Harrisburg while Conrail (the merger of Penn Central, the Reading Company, and several other Class I railroads) took ownership of the remaining part of the line and the many branches, both electrified and non-electrified, that the Penn Central had owned. Amtrak took over the express Harrisburg-New York intercity rail service in 1971, while Conrail, under SEPTA auspices, continued Harrisburg-Philadelphia commuter services. In 1983, SEPTA took over all commuter services and extended operations to Parkesburg (later truncated in 1996 to Downingtown, but later extended to Thorndale). Penn Central made an agreement with the federal government to provide a high-speed service called the Metroliner, which upgraded the Northeast Corridor tracks between New York and Washington by 1969, but neglected other areas such as the Keystone Corridor, a lack of maintenance that continued after Amtrak's takeover in 1976. The Keystone Corridor eventually served as a "depository" for the problem-prone Metroliner electric multiple unit cars. Amtrak also used electric locomotive-hauled trains for Harrisburg-New York service. Before the introduction of Acela electric high-speed service over the Northeast Corridor, and after facing a shortage of electric locomotives (both E60 and AEM-7 models), Amtrak used GE Genesis diesel locomotives between Harrisburg and Philadelphia, with an engine change to an electric (usually AEM-7) locomotive at 30th Street Station. Due to the slower schedules combined with higher ticket prices and competition from SEPTA, ridership declined. The line between Philadelphia and Lancaster was four tracks until the 1960s, when the PRR removed two of the tracks west of Paoli. The line is now two tracks from Paoli to Harrisburg, save for a three-track section between the Glen and Park interlockings, and a four-track section between the Downs and Thorn interlockings. As of 2004, most of the track was limited to a maximum speed of , except for a few 90 mile per hour (145 km/h)) sections between Downingtown and Lancaster. There are also curves which require slower speeds (especially in the section between Merion and Overbrook), and speed restrictions within interlocking limits. High-speed corridor In 1999, the Keystone Corridor was formally