to use mechanical interlocking control towers to regulate rail traffic. , the LIRR has 8 active control towers. All movements on the LIRR are under the control of the Movement Bureau in Jamaica, which gives orders to the towers that control a specific portion of the railroad. Movements in Amtrak territory are controlled by Penn Station Control Center or PSCC, run jointly by the LIRR and Amtrak. The PSCC controls as far east as Harold Interlocking, in Sunnyside, Queens. The PSCC replaced several towers. The Jamaica Control Center, operational since the third quarter of 2010, controls the area around Jamaica terminal by direct control of interlockings. This replaced several towers in Jamaica including Jay and Hall towers at the west and east ends of Jamaica station respectively. At additional locations, line side towers control the various switches and signals in accordance with the timetable and under the direction of the Movement Bureau in Jamaica. Signal and safety systems Today's LIRR signal system has evolved from its legacy Pennsylvania Railroad (PRR)-based system, and the railroad utilizes a variety of wayside railroad signals including position light, color light and dwarf signals. In addition, much of the LIRR is equipped with a bi-directional Pulse code cab signaling called automatic speed control (ASC), though portions of the railway still retain single direction, wayside-only signaling. Unlike other railroads, which began using color-light signals in the 20th century, the LIRR did not begin using signals with color lights on its above ground sections until 2006. Some portions of the railway lack automatic signals and cab signals completely, instead train and track car movements are governed only by timetable and verbal/written train orders, although these areas are gradually receiving modern signals. Many other signals and switching systems on the LIRR are being modernized and upgraded as part of the Main Line's Third Track Project, most notably at Mineola, where the system is being completely redone and modernized. On portions of the railroad equipped with ASC, Engineers consult the speed display unit, which is capable of displaying 7 speed indications. They are 80,70,60,40,30,15 on electric trains while some diesel locomotives have slightly lower speed-steps when compared to the electrics. As a result of a December 1, 2013, train derailment in the Bronx on the Metro-North Railroad, railroads with similar cab signal systems to Metro-North, such as the LIRR, were ordered to modify the systems to enforce certain speed