KANSAS CITY, Mo. (AP) — Amtrak officials say a tentative agreement has been reached that would keep the Southwest Chief passenger train running in Kansas and Missouri. Amtrak had threatened to shut down or reroute the Southwest Chief in Kansas and to stop the River Runner service between Kansas City and St. Louis. The dispute involved funding federally-required safety systems designed to prevent accidents caused by human error. A rail company that routes trains through the Kansas City metropolitan region said it could not afford to install the positive train control systems. Federal law requires that the system be installed by the end of the year. Amtrak spokesman Marc Magliari said in a statement Monday that a tentative agreement was reached to keep the trains running. He said details of the agreement are not final.