Traffic signals are used to control traffic at intersections, crosswalks, schools, and fire stations. All signals must be designed and installed in compliance with the Maryland Manual on Uniform Traffic Control Devices. The Traffic Engineering Division designs, installs, and maintains signals using its own forces, contractors, and consultants. We maintain approximately 100 full traffic signals at intersections, as well as a number of school zone signals, fire station signals, and speed monitoring devices. To reduce operating costs and improve safety, the County has completed a switch from incandescent bulbs to energy-efficient light emitting diode (LED) fixtures and has installed battery back-up units to keep signals operating in the event of a power failure. 
While signals can provide easier access for side street traffic and reduce right-angle collisions, they can also increase congestion and rear-end accidents on the major road of the intersection. Accordingly, signals are installed only after a careful study is completed of the intersection and its traffic volumes. If you would like to request a signal study, please contact the Traffic Engineering Division at 410-222-7331 between the hours of 7:30 a.m. and 4:30 p.m., Monday through Friday. Your request will receive an initial investigation by our engineering staff within one week. However, the study may require several months to complete in order to allow for the collection and analysis of data. The actual design and installation of a new traffic signal typically takes six to twelve months. To request repair of an existing traffic signal, please call the Traffic Maintenance Shop at 410-222-1940 between the hours of 7:00 a.m. and 3:30 p.m., Monday through Friday. After hours traffic signal outages should be reported to 410-222-8400. Please provide as much specific information as possible; i.e., is the entire intersection dark or flashing, which bulbs are out, was there an accident that damaged our equipment, are there poles, signals, or wires impeding traffic, etc. Technicians will respond to signals that are flashing or not functioning within two hours, 24 hours per day, 365 days per year. Non-critical repairs, such as a single bulb out, will be made as soon as possible, usually the next business day. | 
