If a signal is dark, call 911. If a signal is malfunctioning and in unincorporated Snohomish County, call 425-388-6420 or complete a request form. If the signal is on a state highway, contact the WA State Dept. of Transportation Traffic Management Center at 206-440-4490. Wherever it is, if the signal is dark, always treat the intersection as a four-way stop.