Roadway lighting is intended to produce quick, accurate, and comfortable seeing at night that will safeguard, facilitate, and encourage vehicular and pedestrian traffic. SDOT is responsible for ensuring the proper street lighting levels and permits street and pedestrian lighting requests.

Standard Plans, Section 500 Signalization/Lighting
Standard Specifications, Section 8-30 Illumination and Electrical Systems
Standard Specifications, Section 9-31 Illumination and Electrical Materials

Conformance with Local, State and National Standards: The design of all electrical and lighting systems shall be in conformance with the Seattle Municipal Code and National Electrical Code, the National Electrical Safety Code, Washington State Electrical Code Chapter 296-454 WAC.

New or relocated roadway lighting—non-arterial streets : Street lighting for non-arterial streets should be designed using the most recent edition of the recommended IES guidelines, unless otherwise approved by Seattle City Light (for example, according to the 1993 edition of IES standards, standard values for a residential asphalt collector street are 0.6 maintained foot candles, 4:1 uniformity, and a maintenance factor of at least 0.69).

Arterial Street lighting: Generally, most new street lighting systems are designed using the recommended IES guidelines. Where practical, SDOT will require street lighting to meet or exceed these guidelines. During the review process additional information on type and style of luminaires will be provided. To maintain reliability and maintenance only fixtures approved by SCL will be acceptable.

Conduit : When new sidewalk and/or curb is installed along an arterial street and no adequate conduit exists for SDOT communication or street lighting, the SDOT Traffic Engineer may require the applicant to install these facilities.

Pedestrian lighting : Pedestrian lighting illuminates the pedestrian walkway and is typically located 12 feet-15 feet above the sidewalk. This lighting is not normally considered in the calculations for maintained foot candles and uniformity of roadway lighting. However, there are exceptions when considering the newer, more efficient luminaries and their lighting output.

Pedestrian ways, not adjacent to the roadway, should have 2.0 maintained foot candles (where practical). For additional information about lighting on non-arterial streets, contact Seattle City Light.

Refer to Figure 4-21 Pedestrian Lighting Sections.

Street light and traffic signal poles, fire hydrants, and other above-ground fixtures are placed to leave sufficient clearance for pedestrian traffic. Get more information on standard clearances.

In some instances, planting strips can also provide space for utilities (both above and below ground) such as power poles and electrical lines, street light poles and conduits, fire hydrants, and cable television conduits.