This past December, we shared an update on the work we’re doing to improve Link light rail service—specifically, how we’re digging into the root causes behind recent unplanned disruptions on the 1 Line and 2 Line and working to make your Link trips more reliable.
Over the past three months, we’ve completed a range of “quick fix” repairs and other improvements, and we want to update you on how those have paid off in the past few months.
At the same time, we also commissioned an independent assessment of the entire Link system to explore the causes of our recent increase in disruptions and recommend potential solutions.
Improvements since December are reducing disruption times
In our last update, we outlined the most frequent causes behind unplanned service disruptions: issues with our Series 2 light rail vehicles, signal malfunctions within the train control system, and electrical outages in our traction power system.
Since then, Sound Transit and our Link operating partner, King County Metro Rail, have been working together closely to score some quick wins in all three categories. That’s included tasks like:
Cleaning the tracks in the downtown tunnel to reduce electrical faults caused by debris.
Improving our response to power loss, so troubleshooting crews deploy more quickly and issues clear faster.
Training Link operators on how to clear brake faults (a performance issue, not a safety concern, but can lead to service interruptions) so they can resume service more quickly.
Enhancing how we inspect overhead wires that power the train and track switches.
Catching up on repair backlogs.
The good news is that these fixes are paying off for our passengers.
In December, we shared a graph similar to the one below, showing 2024 year-to-date data (from January through mid-November) on the duration of interruptions.
Now, in pink, you can see some significant improvement from the time frame of Nov. 1 through Feb. 19 of this year, across all three categories:
As the three pink columns show, monthly service disruption hours are down by more than half in the past four months—from 5.3% of the time to 2.5%.
This is a great start, but it’s just that—a start. We know that 2.5% is still too high for our passengers.
And while total disruption time has improved significantly in the past few months, the number of disruptions has not improved.
We’re seeing fewer severe disruptions that affect operations for a long time, but still a very high number of small disruptions, particularly with light rail vehicle issues. These can be as simple as a train needing to go out of service and riders experiencing a 10-minute delay.
You can see the recent increase in number of disruptions shown in pink in the graph below:
There is an important caveat here, though: Part of the increase shown in the graph above is due to our new alert system, which has been tracking smaller disruptions that would not have been recorded before. This can account for some but not all of the increase.
What’s clear is that our riders haven’t seen a marked improvement in the frequency of disruptions.
And in the big picture, these results are generally what we expected, because there are limits to what we can achieve with quick, near-term fixes.
We know the highest-impact improvements will take some time and investment, and we now have a road map to tackle what’s next.
Going forward: Systems assessment recommendations
In September 2024, Sound Transit staff commissioned the independent “Link Operating Systems Resiliency Assessment,” and we shared the findings from the final report with Boardmembers and the public at the March 6 meeting of the Board’s Rider Operations and Experience Committee.
The vast majority of the recommendations in the report are technical in nature, prioritized as immediate-, short-, and long-term actions to improve system resilience.
In addition to technical items, the report also recommends ways to improve collaboration, standardize protocols, and adopt clearer shared accountability measures between Sound Transit and our operating partners at King County Metro.
The REO committee presentation focused on the technical aspects of the report, since we believe they’re the most acute issues in terms of boosting near-term performance and reliability.
They include recommendations for almost every facet of our operations, from modernizing our communications network (the backbone that provides stability for all our other systems), to adding more crossover tracks to limit single-tracking when maintenance happens.
Knowing better, doing better
In the process of comparing our own internal reviews and the external report recommendations, we’ve taken the opportunity to step back and assess the big picture.
Taken together, the findings are illuminating.
They collectively highlight how we have struggled – and sometimes failed – to properly balance light rail expansion work with a sufficient and systematic focus on service quality.
Going back several years, even before the COVID pandemic, we devoted major energy and resources to overcoming construction challenges and market pressures to open new service as rapidly as possible.
Many of our current operating issues are emergent symptoms of this latent imbalance. We didn’t adequately and comprehensively account for how “scaling up” our various systems would introduce new stresses and points of failure.
With six major extensions opening between 2021-2026, these issues have occasionally compounded and overlapped due to the sheer pace of work, inhibiting our ability to focus solely on the operating implications of each individual opening.
And at a certain point, continued expansion has caused many of these issues to hit critical “breaking points” and reveal themselves for the first time.
Several systems began to experience simultaneous stress and breakage in the wake of: 1) opening the 2 Line and the 1 Line extension to Lynnwood in 2024, and 2) simultaneously working to integrate the systems between the 1 and 2 Lines in preparation for interlining them in 2025.
It’s become clear that we need to focus more closely on the implications of plugging new systems into the existing ones to ensure a smooth transition.
We take accountability and ownership of these oversights and failures to plan.
We now have a roadmap forward, both in identifying technical issues and broader concerns.
None of these issues represent fatal or unfixable structural flaws in our system. They’re each addressable with sufficient time, funding, and expertise to discover and remedy them.
Some technical issues are easier to fix, particularly those that arise due to issues in maintenance, documentation, and partner collaboration.
Other technical issues are much more difficult to fix, particularly those inherent in system design, such as the placement of rail crossovers in downtown Seattle and in Lynnwood that reduce operating flexibility, and which would require lengthy service disruptions to retrofit.
But overall, we want to assure you that we are giving these issues the seriousness and resources they deserve, and that we’re on the right path to providing the quality of service you rightfully expect.
Despite operating challenges, we want to thank you for sticking with us and continuing to vote with your feet about the value that Link brings to your lives. Ridership is higher than ever, averaging 123,000 daily boardings in January 2025 – more than 10 times the ridership of the highest-ridership bus route in the region (Rapid Ride E).
The Link light rail system is an essential regional asset that hundreds of thousands of people depend on, and we pledge to you that we’re going to treat it with that level of importance going forward.
We want to keep you informed on how our Link reliability and resiliency work continues to progress, so stay tuned for another update soon.