Shore Line East provides access between Old Saybrook and New Haven Monday through Friday, with Shore Line Express service to and from Bridgeport and Stamford. Connections to New Haven Line and Amtrak service are available at New Haven's Union Station.

Metro North's New Haven Line has three branches providing connecting service in Connecticut- the New Canaan Branch, Danbury Branch and Waterbury Branch. At New Haven, the Shore Line East connecting service, which is run by Connecticut, continues east to New London.