The '''Caltrain Express Program''' ('''CTX''') project was implemented from 2002 to 2004 to establish the '''Baby Bullet''' express service, which shortened the transit time on the [[Caltrain]] commuter rail line between [[San Francisco]] and [[San Jose, California|San Jose]], and certain stations in between. New locomotives and rolling stock were purchased for dedicated express service, bypassing most stations; [[Quadruple-track railway|quad-track overtake sections]] were added in two locations along the Peninsula Corridor right-of-way to allow express trains to pass slower local trains that were making all stops; tracks were also upgraded with [[Track (rail transport)#Continuous welded rail|continuous-welded rail]]; a [[centralized traffic control]] system was added; and [[railroad switch|crossovers]] were added every few miles to allow single-tracking trains around disabled trains. Congresswoman [[Jackie Speier]], then serving as a California State Senator, is credited with securing the funding for CTX and one of the new locomotives acquired for the project is named for her as a result. During commute hours, the Baby Bullet went up to 20 percent faster than driving south from San Francisco to San Jose. On September 21, 2024, with the completion of the [[Caltrain Modernization Program|Caltrain modernization project]] and the transition to electrified trains, the Baby Bullet was renamed as simply the '''Express''' service.<ref name=":0" />
