The road over the top of the dam is one of four arteries for crossing the Croton River ( only three of the bridges connect to public roads at both ends ) . Following the September 11 attacks in 2001 , this road has been closed to non-emergency vehicles as a security precaution , though it remains open to pedestrians and bicycles . Previously , school buses had used the road as the best route available
September 11 attacks
September 11 attacks
Croton Gorge Park