Since the early days of rail transport in the United States, Philadelphia has served as hub for several major rail companies, particularly the Pennsylvania Railroad and the Reading Railroad. The Pennsylvania Railroad first operated Broad Street Station, then 30th Street Station and Suburban Station, and the Reading Railroad operated out of Reading Terminal, now part of the Pennsylvania Convention Center. The two companies also operated competing commuter rail systems in the area, known collectively as the Regional Rail system. The two systems today, for the most part still intact but now connected, operate as a single system under the control of the SEPTA, the regional transit authority. Additionally, the PATCO Speedline subway system and NJ Transit's Atlantic City Line operate successor services to southern New Jersey.