Saw Mill Parkway by the Marble Avenue exit in Thornwood is horrible, especially the northbound lanes. Leading up to the traffic light, the road is damaged with ruts and potholes. This can result in momentary loss of control, and is startling to drivers who are not aware of the road's condition. A friend of mine thought something was wrong with the tires on his few months old at the time car when he approached the intersection northbound. No, it;s just the crummy road, I told him.