The junction serves as the western terminus of NY 347 and the eastern terminus of the Northern Parkway. NY 347 and NY 454 become concurrent, crossing through Hauppauge and residential properties for the next two miles (3.2 km), intersecting with local roads. After bending around Forestwood Park, Routes 454 and 347 follow the town line and pass the Stoubrough Golf Course, where NY 347 forks to the northeast.
The junction serves as the western endpoint of NY 347 and the eastern terminus of the Northern Parkway. NY 347 and NY 454 become concurrent, traversing through Hauppauge and residential properties for the next two miles (3.2 km), intersecting with local roads. After curving around Forestwood Park, Routes 454 and 347 follow the town boundary and pass the Stoubrough Golf Course, where NY 347 branches to the northeast.