The Superintendent of Highways, in cooperation
with the Chief of Police, shall install and maintain traffic control
devices when and as required under the provisions of this chapter
to make effective the provisions of said chapter and to install and
maintain such additional traffic control devices as he may deem necessary
to regulate, warn or guide traffic under the Vehicle and Traffic Law
of the State of New York, subject to the provisions of §§ 1682
and 1684 of that law.