It's been a particularly tough week on the Red Line. T officials say old cars and freezing temps are to blame.

The T is running less than half as many trains as usual on its busiest subway line after it pulled some of its oldest trains ...

A delay on the MBTA because of a "signal problem" is a regular occurrence. But for many MBTA riders, what that means is a mystery. Simply put, the signal system is "the intelligence that helps trains ...