The only portion of 9W that's dicey is the stretch past CNBC, about 1 mile between the Englewood Cliffs and Tenafly traffic lights. The rest has a wide shoulder. But that's a bit deceptive, 9W is a road where cars can routinely do 60 mph and can hit 80 mph. Wide shoulder or not, that's a potential problem for cyclists going 10-25 mph on the shoulder. That being said, the number of fatalities involving cyclists seems rather low given the large volume of bicycle trips up and down the road. I've lived near 9W for my entire life (graduated high school in Demarest, lived on the East Hill in Closter, about 1 mile down the hill from 9W) and I know the road like the back of my hand. I don't feel unsafe on 9W, but I'm glad I don't have to ride it on a daily basis.