Waterbury Branch

Metro-North Railroad's Waterbury Branch is a branch of the New Haven Line, running north from a junction in the Devon section of Milford to Waterbury. Originally built as the Naugatuck Railroad, it once continued north to Winsted. The part north of Waterbury is now leased from CDOT by the Railroad Museum of New England, which operates excursion trains from Thomaston station; that part is still called the Naugatuck Railroad (reporting mark NAUG). The trackage ends in Torrington but Metro North service on the branch ends at Waterbury. There are conceptual plans to extend service from its current terminus in Waterbury to Hartford via Bristol and New Britain.

There are no trains that travel directly from the Waterbury Branch to Grand Central Terminal; however, one AM peak train stops in Stamford, where passengers can transfer to a train bound for GCT.