Complex sentence: Although the line was a host for the UMTA's State of the Art Car program, real replacements for the Broad Street cars did not come until 1982, when SEPTA introduced new "B-IV" cars built by Kawasaki.
Split into simpler sentences: Although the line was a host for the UMTA's State of the Art Car program, real replacements for the Broad Street cars did not come until 1982. At that time, SEPTA introduced new "B-IV" cars built by Kawasaki.