Canadian Pacific Kansas City (CPKC) and CSX have upgraded their Southeast Mexico Express (SMX) intermodal service, introducing a dedicated train and revised schedules from 4 May 2026. The changes reduce transit times between the U.S. Southeast, Texas and Mexico, including a two-day service between Atlanta and Dallas.
The new schedule provides three-day transit from Monterrey to Atlanta and four days from central Mexico to Atlanta. According to the operators, transit times across all existing SMX lanes have been reduced, with improvements of around one day between Atlanta and Dallas and approximately 2.5 days between Atlanta and central Mexico.
The service links markets including Atlanta, Charlotte and central Florida with destinations such as Dallas and Monterrey. New origin and destination options include Charlotte, Jacksonville and central Florida.
The improvements follow infrastructure investments on the former Meridian & Bigbee Railroad (MNBR), including upgrades to track, bridges and signalling, as well as corridor works across Georgia, Alabama, Mississippi, Louisiana and Texas. CPKC and CSX established a direct Class I interchange near Myrtlewood, Alabama, after acquiring sections of the former MNBR.
SMX was launched in December 2024 as an east–west rail corridor connecting the U.S. Southeast with Texas and Mexico. The service targets intermodal, automotive and carload traffic and is positioned as a rail alternative to long-haul trucking on these lanes.
