The new US route used the entirety of Ridge Road from Lewiston to Red Creek, save for small portions in and around the city of Rochester; as a result, NY 31 was shifted south onto most of its modern alignment while NY 3 was rerouted south of Watertown to follow what had been NY 3D. When US 104 was first assigned, it dipped south to serve downtown Rochester instead of bypassing it to the north.
The new US route utilized Ridge Road from Lewiston to Red Creek, with only minor sections within and around Rochester being excluded. This led to a shift in NY 31's alignment southward while NY 3 was rerouted south of Watertown along the former path of NY 3D. Additionally, when US 104 was first assigned, it initially served downtown Rochester instead of bypassing it to the north.