Valley Rail is a project to expand Altamont Corridor Express (ACE) and Amtrak California San Joaquins commuter rail services, divided into several segments which include two service extensions from Stockton to Sacramento and Merced, station improvements, and grade separation of the Stockton Diamond., ACE is planning for an extension of the line from Stockton to Sacramento. Project elements: Extension would operate on one of the two UP owned corridors between Sacramento and Stockton., The current Altamont Corridor Express route. ACE. MODESTO, Calif. — Planned expansion of the Altamont Corridor Express commuter rail service into Stanislaus and Sacramento counties will be delayed by two years, with the first trains not running until 2026, the Modesto Bee reports., The Altamont Corridor Express (also known as ACE, formerly Altamont Commuter Express) is a commuter rail service in California, connecting Stockton and San Jose during peak hours only. ACE is named for the Altamont Pass, through which it runs., The city of Modesto’s transit center on Ninth Street has been revamped its former train station in anticipation for ACE train service. ACE also plans to extend a line to Sacramento. Other new stations opening by the end of 2026 are in Modesto, Oakley, Natomas, midtown Sacramento and Elk Grove., Amtrak San Joaquins: San Joaquins trains serving Sacramento stop at the ACE Robert J. Cabral Station. (Note: San Joaquins trains serving Oakland stop at the San Joaquin Street Station.) Limited Amtrak San Joaquins Bus service..