On Saturday, December 6, Seattle’s regional transit system reached a major milestone with the completion of the (FWLE) — largest design-build project to date.
Ahead of opening day, months of pre-revenue testing helped prepare the new light rail system for reliable service. Running trains without passengers allowed teams to validate performance, coordinate systems and fine-tune operations — helping create a smooth and confident start for riders.
Hundreds of people participated in the grand opening celebrations, attending the cultural activities, exhibits and entertainment at each of the new stations. In partnership with Sound Transit, Atlas is proud to have contributed to the delivery of this important expansion — part of a broader vision (F200 link extension) to build a 252-mile regional light rail network connecting communities across three counties.
Expanding Access Across the Region
The FWLE adds 7.8 miles of light rail service, extending the line from Angle Lake Station to Federal Way.
With three new stations — Kent Des Moines, Star Lake and Downtown Federal Way — the expansion strengthens connections across South Puget Sound, offering a faster, more reliable way to reach the airport, workplaces and community destinations.
By improving mobility and reducing travel time, the project supports a more connected region and enhances everyday access for residents and visitors alike.
Supporting Quality from Start to Finish
Atlas teams played a key role in supporting quality throughout project delivery — from early utility coordination to final system readiness.
In the early stages, efforts included coordination tied to major infrastructure elements such as waterline relocation. As the project progressed toward completion, the focus shifted to quality assurance and readiness activities that helped bring the system to opening day.
Together with Sound Transit, Atlas supported the project through a multidisciplinary approach spanning quality, environmental, engineering and survey services. Over the course of the program, teams completed an estimated 40,000 inspections, helping maintain consistency and alignment across complex construction activities.
On peak construction days, that effort required significant coordination — completing dozens of hold point inspections and multiple concrete placements in a single day, supported by a team of inspectors and technicians working across the project footprint. Atlas’ Quality Assurance team also coordinated with dozens of contractors, subcontractors, agencies and local jurisdictions, helping keep work moving forward in a highly collaborative environment.
The scale of construction required equally significant materials oversight. Atlas teams supported approximately 163,000 cubic yards of concrete placement, along with the testing of more than 37,000 concrete cylinders to verify performance and quality throughout the build.
This continuity across phases — and the ability to scale with the project — helped maintain alignment across teams, contributing to a delivery experience grounded in consistency, collaboration and attention to detail.
Built for Communities
Transit investments like the FWLE are ultimately about connection — linking people to opportunity, reducing congestion on key corridors like I-5 and creating more reliable options for how communities move.
With expanded light rail access, residents can spend less time in traffic and more time where it matters most — whether that’s work, home or the places that bring communities together.