Extending the Bethpage northward was a requirement for building the new parkway, and four new interchanges were proposed for the Bethpage Parkway. The first, exit B5, would be at NY 135 (the Seaford–Oyster Bay Expressway). With this new interchange, the traffic circle with Plainview Road in Bethpage State Park would be eliminated. Other junctions included a diamond interchange for Plainview Avenue and Bethpage State Park, a full cloverleaf interchange with Old Country Road, and a partial cloverleaf interchange with the Long Island Expressway (then-NY 495). North of there, the new Caumsett exits would be a full cloverleaf interchange with the Northern State Parkway, a diamond interchange with NY 25 (Jericho Turnpike) and an interchange with NY 25A and NY 108. After the NY 25A interchange, the parkway would continue north into Caumsett State Park and end at a traffic circle at the southern end of the park.