Contractor crews working for King County Metro will soon start construction on the Atlantic Base Yard Facility to improve the overhead wires that power trolley buses and additional infrastructure improvements. The majority of the work will occur during normal business hours with intermittent nighttime work. This work is expected to be completed by 2028.

Longtime home to trolley fleet

Atlantic Base was expanded to store 200 trolley buses between 1979 and 1980. To accommodate this, the parking lot was constructed of Portland cement concrete panel (PCCP) and 4 to 6 inches of gravel base. Existing concrete panels are typically 17 by 22 feet, with some built in 1979 and the rest earlier. Several areas were repaired or replaced as part of the base’s regular maintenance program, and in several areas concrete panels have been overlaid with asphalt concrete, mainly along the perimeters of the site.

In 2016, King County Metro contracted engineers to assess and monitor the conditions of our facilities. From these assessments, a Transit Facilities Conditions Needs Report identified capital improvements needed at the Atlantic Base parking lot. The report recommended removing and replacing concrete panels in the bus parking areas of the Atlantic Base Site trolley yard in coordination with utility replacement projects.

Project delivers improved concrete lot, utilities, trolley wires

This project will replace all concrete paving and underground infrastructure, including storm drainage, sanitary sewer, industrial waste, and buried power lines, as well as rehabilitating underground storage tanks. Additionally, the existing overhead catenary system will be upgraded to support KCM’s expanding electric trolley fleet.

Once complete, this project will provide the proper infrastructure necessary to support the storage of Metro’s growing fleet, and replacement, maintenance and upkeep of the bus yard infrastructure.

The construction project cost is estimated to be $45 million and will be built by Granite Construction in multiple phases to ensure the uninterrupted operation of bus service operating from King County Metro’s Atlantic Base.

What to expect during construction

Crews will take the following steps to limit noise:

• Construction equipment will be equipped with no pure tone back up alarms.
• Use approved bed liners in trucks.
• Avoid excessive tailgate banging.
• Provide a complaint number to track any reported issues.

Nighttime work and its impact

Businesses near and with direct line of sight of Airport Way and South Royal Brougham will hear occasional noise from crews using excavation equipment, drill rigs, and generators during intermittent work in the evening and overnight. We apologize for any inconvenience this causes and appreciate your patience while crews perform this important work.

Contact information

Communications
206-263-9768
community.relations@kingcounty.gov