It shall be the duty of the traffic division with such aid as may be rendered by other members of the police department to enforce the traffic regulations of the local authority, to make arrests for traffic violations, to investigate accidents and to cooperate with the traffic engineer and other officers of the local authority in the administration of the traffic laws and in developing ways and means to improve traffic conditions, and to carry out those duties specially imposed upon the said division by this chapter and the traffic ordinances of the local authority.