Past this interchange, the freeway enters the town of East Haven, where US 1 parallels the highway on the both sides as a frontage road as the southbound direction narrows back to three lanes, before coming to a partial interchange with that route. Within the interchange, it also crosses the Northeast Corridor. A short distance later, there is a southbound exit and northbound entrance with Route 100 before the road curves east across Saltonstall Mountain and Lake Saltonstall, and comes into the town of Branford. Within this area, I-95 passes through the Stewart B. McKinney National Wildlife Refuge where it comes to an northbound exit and southbound entrance with the Branford Connector, that connects to US 1, Route 142, and Route 146 near Short Beach. Just after the connector, there is a service plaza in both directions, and the freeway passes north of the center of Branford. From here, the road narrows to four lanes and continues east into more rural and wooded surroundings, coming to an interchange with US 1 on the east side of town. I-95 briefly enters a commercial area and passes north of the Stony Creek neighborhood. The freeway heads back into wooded areas as it enters the town of Guilford, where it comes to interchanges with US 1 and Route 77 north of Guilford Center. The road continues east across the East River marshlands, and comes into the town of Madison prior to crossing the Neck River. The road heads to the north of Madison Center, where it has an interchange with Route 79 with a park and ride lot in its northeastern corner. Past Route 79, I-95 passes service plazas in both directions, and reaches an interchange with the Hammonasset Connector, which provides access to Hammonasset Beach State Park. At this point, the route crosses over the Hammonasset River and leaves New Haven County.