Greenwich commuters heading to New York City starting Saturday, Sept. 12, will find fewer trains on Metro-North's New Haven Line.

The Connecticut Department of Transportation (CTDOT), Metro-North Railroad and Amtrak announced Tuesday, Sept. 8 that trains will run on modified schedules on select weekends from Sept. 12 through Nov. 1. The disruptions support removal of two 234-foot-tall utility towers and overhead wire systems on the aging WALK Bridge, which crosses the Norwalk River between the East Norwalk and South Norwalk stations.

The first two weekends hit hardest. On Sept. 12–13 and Sept. 19–20, crews will tear down legacy overhead wires that power the electric fleet. Diesel locomotives will replace them, cutting available seating by roughly 55% compared with a normal weekend. Trains will run through the construction zone only about every 90 minutes.

Metro-North said riders should expect crowding because the diesel-hauled trains carry fewer passengers than the regular electric cars.

Local service between Grand Central Terminal and Stamford, including Greenwich station stops, will keep running on its normal schedule with one exception: a single Saturday morning train will be adjusted. CTDOT did not identify which train by number or departure time. Riders should check the MTA TrainTime app or visit MTA.info/alerts for specifics.

Two later weekends, Oct. 10–11 and Oct. 17–18, will also see reduced service, though the impact should be lighter. Electric trains will continue running through the work zone on those dates, with about 30% fewer seats available, according to Metro-North as reported by the New Haven Register.

A fifth affected weekend has not been specified beyond the Nov. 1 end date.

Amtrak service between New York and New Haven will also be sharply limited during the construction weekends. As of Wednesday, Sept. 9, Amtrak's website showed many weekend trains already canceled.

CTDOT is offering free parking at the Stamford Transportation Center on affected weekends. Paid parking is also available at the South Norwalk Parking Garage. The agencies encouraged riders heading to or from New York to drive to Stamford or South Norwalk and catch the more frequent local trains from there.

The WALK Bridge replacement is a $1.6 billion project, according to Metro-North, to replace the roughly 130-year-old span over the Norwalk River.

Riders can check updated schedules and service alerts through the MTA TrainTime app, MTA.info/alerts, or the Amtrak app.