Three days after a computer update problem caused more than 5,000 flight cancellations around the world in a single day, things are pretty much back to normal — except at Delta Air Lines.

A system-wide computer problem stalled four South Shore Line trains at their stations between 20 and 45 minutes Tuesday afternoon. The issue was with Positive Train Control, the computer-operated ...

BART trains didn't run for seven hours because of a computer equipment problem. This is the fourth major BART outage issue since May. Commuters were left to find alternative modes of transportation ...