RCW 46.61.085Traffic control signals or devices upon city streets forming part of state highways—Approval by department of transportation.No traffic control signal or device may be erected or maintained upon any city street designated as forming a part of the route of a primary state highway or secondary state highway unless first approved by the state department of transportation.[ 1984 c 7 s 62; 1965 ex.s. c 155 s 14.]NOTES:Local authorities to provide stop signs at intersections with increased speed highways: RCW 46.61.435.
Washington Legal Code