Speed Camera or Speed Trap

 

As a car goes over the West 239th Street overpass of the Henry Hudson Parkway and continues to travel south on Riverdale Avenue the roadway begins to have a downward slope picking up speed. You then approach a light at West 238th Street, where cars can speed up to beat the light. However there is something that the NYCDOT has placed on the light pole in the foreground that is magnified in the next photo.

There is a speed camera perched on the light pole at Riverdale Avenue South and West 238th Street. Yes there is a school across the street, or at least a driveway to the school and a large athletic field. Also there is no speed camera in the northbound direction since that is uphill where the drivers are going much slower than traveling downhill. 

So is this a speed camera or a speed Trap?