Railways companies, and thus routes, were largely consolidated under a few Class I railroads by the end of the century. In 1982, the Union Pacific Corporation purchased the Western Pacific and the WP became part of a combined Union Pacific rail system: the Union Pacific Railroad, the Missouri Pacific Railroad, and the Western Pacific. Southern Pacific was purchased by Union Pacific and acquisition was finalized in 1996. In the same year, the ATSF merged with the Burlington Northern Railroad to form BNSF Railway. With those two mergers, the two major railroads in California became Union Pacific and BNSF, with some smaller short line and switching operations. Line abandonment has generally increased since then, as redundancies are reduced. The Union Pacific line over Tehachapi Pass operates as one of the busiest single-track railways in the world.