Sagtikos State Parkway - Route Description

Route Description

The Sagtikos State Parkway begins at an interchange with the Southern and Heckscher state parkways in the hamlet of West Islip, just north of the Robert Moses Causeway's junction with the Southern State Parkway. Heading southbound, this junction is signed as exit S4. The parkway proceeds northward through the town of Islip as a four-lane divided highway, passing through residential parts of the adjacent hamlet of Brentwood to reach exit S3, a partial cloverleaf interchange with Pine Aire Drive. Just north of the junction, the highway passes over the Main Line of the Long Island Rail Road. Continuing northward through Islip, the Sagtikos Parkway leaves Brentwood ahead of exit S2, a connection to County Route 13 (CR 13, named Crooked Hill Road). The southbound exit serves CR 13 by way of access roads through the Pilgrim Psychiatric Center while the northbound direction uses part of G Road to reach CR 13 and Suffolk County Community College's Grant Campus.

Past the exit, the Sagtikos State Parkway crosses under CR 13 and immediately enters exit S1, a large modified cloverleaf interchange with the Long Island Expressway (Interstate 495 or I-495). The junction brings the parkway into the town of Smithtown, where it bends northwestward and parallels CR 67 (Vanderbilt Motor Parkway) for a half-mile (0.8 km) through the town's Commack section. CR 67 eventually turns westward to pass under the Sagtikos Parkway, at which point the parkway curves back to the north and enters exit SM1E, a cloverleaf interchange serving as the Northern State Parkway's exit 44. The Sagtikos State Parkway name ends here while the highway continues northward toward Long Island's North Shore as the Sunken Meadow State Parkway.

According to annual average daily traffic counts compiled in 2011 by NYSDOT, the most-traveled stretch of the Sagtikos State Parkway was the portion between the Southern State Parkway and the Long Island Expressway. The part between the Southern State and Pine Aire Drive handles an average of 87,250 vehicles per day; less but similar numbers were recorded along the segment between Pine Aire Drive and the Long Island Expressway, with roughly 85,300 vehicles using the section on a daily basis. The portion between the Long Island Expressway and the Northern State Parkway carries an average of 67,600 vehicles per day. All three segments saw a rise in traffic over the course of the previous decade, with the Pine Aire Drive–Long Island Expressway segment gaining 14,000 vehicles per day during that time.