a. The City Traffic Engineer or his authorized representatives shall place and maintain or remove traffic control devices as required under the traffic ordinances of the City or State law to make effective the provisions of said ordinances and law and may place, maintain or remove such additional traffic control devices as he may deem necessary under the traffic ordinances of this City, or under State law.

b. Such traffic control devices shall conform to the Manual on Uniform Traffic Control Devices as adopted by the Arizona Highway Commission.

c. It shall be the general duty of the City Traffic Engineer to determine the installation and proper timing and maintenance of traffic control devices; to conduct engineering analyses of traffic accidents, and to devise remedial measures; to conduct engineering investigation of traffic conditions and to cooperate with other City officials in the development of ways and means to improve traffic conditions and carry out the additional powers and duties imposed by ordinances of this City. (Code 1962, § 37-3.01)