Complex sentence: Until the 1990s, when US 20 was diverted to a limited-access highway to the south of Elkhart, Indiana 120 had its western terminus in Elkhart on US 20; after the re-alignment of US 20, Indiana 120 was truncated at a street junction.
Split into simpler sentences: Until the 1990s, when U.S.20 was diverted to a limited-access highway to the south of Elkhart, Indiana 120 had its western terminus in Elkhart on U.S.20. After the re-alignment of U.S.20, Indiana 120 was truncated at a street junction.