A section of the Long Island Motor Parkway that exists to some degree today is called Dead Man's Curve in Bethpage. Indicated by the blue hilight in the map at left, it lies west of today's Seaford Oyster Bay Expressway and south of Central Avenue. The road on the western side (i.e. the left) of the map in yellow is Stewart Avenue. The curve began by proceeding east at the south end of North Hermann Avenue, curving north and running parallel to the western side of today's Seaford Oyster Bay Expressway (which wasn't built until much later on). While looking for remnants of the Motor Parkway in the woods in which Dead Man's Curve is located, I met a resident of Hermann Avenue who indicated that the wooded area is often used by teenagers for late night gatherings, some more eventful of others, but nothing that gets out of hand, especially when the local police officers are called. Seeing me taking pictures initially concerned him and he explained that many times he has seen housing developers taking pictures and being told of their desire to develop the property (something the homeowner was not in favor of). Hopefully this would never happen, as if it did, it would probably mean the end of Dead Man's Curve. Here are some relics of what's left of Dead Man's Curve.
This map is from a 1935 Hagstrom's and shows Dead Man's Curve and two Toll Gates. One gate is west of Deadman's Curve (on the lower left) and the other is after the Parkway passes through what is now Bethpage State Park (labeled Central Park) - on the top right where Bethpage is indicated.