Expanding public transit for a growing Seattle

LINK

Building on a partnership forged two decades ago on an elevated light rail project in Seattle, we are working closely with the Central Puget Sound region’s transit agency to radically expand its transportation infrastructure for a more sustainable future of community connectivity.

The economy of the US Pacific Northwest has prospered in recent decades, with some of the country’s largest companies headquartered there, including Microsoft, Amazon and Starbucks.

The economic boom has driven population expansion, with the greater Seattle area accommodating 128,000 additional residents between 2010 and 2021 − making it one of the fastest-growing cities in the US. But Seattle’s success has also brought growing pains. The subsequent rise in housing costs has driven its citizens to seek affordable accommodation further from the city centre, contributing to ever-worsening traffic congestion and pollution. And, with the population of the Central Puget Sound area expected to increase from its 2014 level of 2.9M people to a projected 3.7M by 2040, state authorities have responded by accelerating the expansion of the public transportation network.

In 1992, the Washington State Legislature authorised the creation of an agency, now known as Sound Transit, to build and operate a high-capacity transportation system connecting the urban areas of King, Pierce, and Snohomish counties. Since then, the region’s voters have approved a series of measures to fund bus, commuter rail and light rail systems through increases in local sales, property and vehicle excise taxes.

In 2008, Sound Transit 2 (ST2) approved $17.8bn of expenditure over 15 years to more than double the length of the light rail system from 32km (20 miles) to 80km (50 miles), and many of the projects funded under the measure are now close to completion. More recently, the approval in 2016 of Sound Transit 3 (ST3) allocated another $54bn, which will pay for the Central Puget Sound area network to more than double again to 187km (116 miles), with the number of stations totalling more than 80.

Existing and future network

The population of greater Seattle is expected to reach 3.7M by 2040

Five light rail link extensions

Northgate: The most recent addition to the light rail Link network runs for 5.5km (3.4 miles), from Northgate to University District, and includes three underground stations in north Seattle. We are leading a joint venture as the construction-management consulting firm overseeing the systems work.

East Link: We are also overseeing systems work for the 22.5km (14 miles) extension that runs eastward from Seattle’s International District. It is for one of Sound Transit’s most complex and ambitious projects, crossing Lake Washington via a floating bridge to Mercer Island, then on to the city of Bellevue and finally to a new station, Redmond Technology, close to Microsoft’s corporate headquarters. It will provide a more sustainable route for commuters between Seattle and the campuses of the tech giant because part of the route will be built on an appropriated lane of the I-90 highway.

Lynnwood Link: We recently began overseeing systems construction work for the 14km (8.7 miles) extension running north from Northgate to Lynnwood City Center, which will include four new stations and is scheduled to open in 2024.

Everett Link: 25km (15 miles) of ST3-funded new track will connect Lynnwood and Everett. It is the longest and northernmost project in the Sound Transit system and is expected to open between 2037 and 2041. We are a subconsultant on the preliminary engineering and environmental phase work.

Federal Way Link extension: One of the first projects to be built with ST3 funding is the 12.5km (7.8 miles) Federal Way Link Extension. It will have three stations, connecting the cities of SeaTac, Des Moines, Kent, and Federal Way to the light rail network. We are leading a joint venture, overseeing the design-build contractor tasked with providing oversight of the foundations, structures, civil engineering, stations, parking garages, guideway and systems, as well as overseeing the integration, commissioning, and handover processes. Construction is well underway, with systems installation also starting.

Federal Way Downtown station under construction with Mt Rainier in the background

Experience pays dividends

Being a true partner means not just supplying the skills that a client is seeking, but also getting added value from collaboration with the client's staff and drawing on lessons from our depth of experience.

The past decade has seen several examples of our close relationship with Sound Transit.

“In 2016, the agency was under pressure to remain on schedule on the South Link project at Angle Lake, and we were facing some challenges with some of the existing consultants and contractors on the project,” recalls Moises.

Conrad describes Mott MacDonald coming in each week in an advisory role to review the schedule and provide suggestions on commissioning: “We managed to move the needle on Sound Transit’s ability to work with the contractor and to get work delivered on time in September of that year. We did this by asking some questions about how processes could be reordered or done in parallel. For example, if you commission an overhead power cable early and energise it, that places severe restrictions on work that you can do nearby, because of safety. We said that should be pushed right back in the schedule. Those kinds of ideas are born of the experience of having done it before.”

Having had a hand in a large proportion of the construction management of the light rail network’s systems means we are well-placed to know exactly what has been installed. “Recently, Sound Transit has commissioned us to provide a full listing of the light rail system’s assets, including those on other projects, to establish an asset baseline,” says Conrad.

In addition to providing support for its asset management implementation programme, the agency has sought our help with structural inspections. “Mott MacDonald thoughtfully and slowly built a case to support the agency in asset management, not just jumping in, trying to make a buck, but really discerning if it could provide a qualified offering,” says Moises.

Construction of the Beacon Hill station platform tunnels

The complete package

By the early 2010s, our consulting role on infrastructure and structural design work for Sound Transit’s projects was complemented by an increasingly close involvement in construction management for rail systems. While the former comprises large-scale physical projects such as stations and tunnels, the latter includes a wide array of supporting infrastructure including rails, power supply, the train control system, communications, safety and fire control systems, wiring and fibre optics.

Working on the systems side naturally deepened the affinity between client and consultant, says Conrad. “It is more closely aligned to the way the railway is operated, and that allowed us to develop our relationship with Sound Transit, to really understand what they are and what their needs are in terms of serving their communities.”

Sound Transit has a core team of highly capable staff who have established an intercity commuter rail service and regional bus service and have opened four light rail lines with two maintenance facilities in the last 15 years. Now the agency needs to open four more light rail extensions by 2025, while planning, designing and building five further extensions and two more maintenance facilities — and that is just the light rail portion.

The agency is also expanding capacity on its commuter rail service and starting up a bus rapid transit service. In delivering this growth, Sound Transit must compete for resources with other West Coast cities like Los Angeles and San Francisco, which are making smaller but still very significant investments in transit infrastructure.

“They know that to deliver projects, their demand for resources and expertise in Seattle will continue to increase,” Conrad says. “In London, for example, there are thousands of people working for Network Rail and Transport for London. It is challenging for a new agency to build that from scratch. The comparatively short history, developing the roster of experts to call on, and a wider market to support them, emphasises the value of the people that firms like Mott MacDonald can bring in.

“As an international consultant we have that resource and expertise. These are people who have been through commissioning processes, interface management, systems integration. They have delivered similar transit extensions in very busy, tangled urban environments.”

Completed Beacon Hill station

Some of the Mott MacDonald team supporting Sound Transit (left to right): Carrie Oshiro, Pete Brown, Guilherme Pereira, Conrad Fawcett and Harrison Cross

A 23-year journey

Since Sound Transit’s light rail system started operating in July 2009, the agency has grown to employ more than 1100 people. It oversaw a peak of 47.8M passengers in 2019, before the pandemic caused a sharp but temporary decline in ridership in 2020-21.

We have been working alongside the client throughout, gradually earning a position as a trusted partner and advisor. Our deep well of knowledge and experience, both local and international, is being brought to bear in partnering with Sound Transit to overcome the complex construction and process challenges that are inevitably encountered on any such large-scale public transit expansion.

Our involvement began more than two decades ago in 2000, when we provided station design and construction support for one of Sound Transit’s early projects, the Beacon Hill light rail station and tunnel. “It was a smaller agency back then — just a few hundred people building one or two projects at a time,” advises our divisional general manager Conrad Fawcett.

Widening the supply base

Washington State sets targets for lead consultants on public projects to procure a proportion of

services from minority or disadvantaged businesses. Conrad notes that we have exceeded those targets in each of the past eight years: “That helps us with our relationship with Sound Transit because that is a very clear priority for them. But it is also a priority for us because we need to develop the industry resources available to us, so it makes perfect sense for us to support these smaller businesses and help them to grow.”

Considering impacts to the community

The environmental benefits of light rail in terms of providing less carbon-intensive transportation options are unarguable, and the Sound Transit expansion has clear focus on capturing them as soon as possible.

One example is the Lynnwood Link, which is due to open in 2025. “On the day it comes into service, I am told that most bus services from the northern part of the city into downtown will cease to operate,” says Conrad. “The idea is that everybody gets on the light rail. It shows there’s pressure on Sound Transit and their contractors and consultants delivering these projects to provide more options and higher-capacity transit to replace less-efficient alternatives with a frequent and reliable service.”

Providing more options and higher-capacity transit for people across the Central Puget Sound region

Partnership built on trust

Sound Transit wanted a consultant that understood the investment of taxpayer funds, and really thinks about the end users of the systems, mindful of the priorities and pressures of a being a public entity.

Moises Gutierrez, Sound Transit’s chief systems quality officer, says he was impressed by Mott MacDonald’s unique approach to engagement with clients: “It was the commitment to integrity and ethical behaviour, and being very judicious and thoughtful in that engagement.

“This is an exciting programme, but certainly cost escalation is an issue, and there are schedule pressures and third-party concerns. For trust and authority to be lasting, it must be earned. I see Mott MacDonald earning the respect and trust of the agency one day, one conversation, at a time.”

Global expertise

Our global reach enables us to can bring innovative approaches and tested techniques to the US northwest.

“In Europe, rigorous processes for systems-interface management are widely adopted. But in the US, it is a younger, still-developing public transit industry, and the application of some aspects of systems engineering is still maturing,” explains Conrad. “Our systems teams play an integral role helping Sound Transit manage complex interfaces between construction contracts, and we’re a key partner in the commissioning and integrated systems testing process.”

We are also applying innovative digital technologies in the region. “Using our geographic information system on Mott MacDonald’s Moata shared digital solutions platform allows us to input recordings and pictures of where assets are and upload that information to a cloud-based database, which saves a lot of effort in sending people out onto sites to do inspections,” says Conrad.

“We are also exploring the use of flying drones to carry out inspections of Sound Transit’s assets. There is a lot of potential there, particularly for looking underneath a bridge or other elevated structure where physical human access may be problematic.”

Moving to the next phase

The last few ST2 projects are nearing completion and Sound Transit is now gearing up for the first ST3 projects. Conrad believes that the journey of ever-increasing faith between client and consultant that Sound Transit and Mott MacDonald have taken together means the firm is well-placed to play a pivotal role in that next stage.

“For 20 years we have been a trusted consultant providing support to Sound Transit, and we think that we are in an excellent position to help prepare for ST3 and expand our business in the US Northwest,” he says. “ST3 is a huge challenge for the agency and the industry here, but it will deliver a big step up in terms of safe, efficient and regular transportation options, particularly for the communities that need it most, and will have a significant impact on quality of life for the people in those communities.”

Construction progressing along the Federal Way Link extension

Construction progressing along the Federal Way Link extension

Ferry decarbonisation

At the end of 2022, we secured a crucial role in another of the city’s innovative new transportation projects. Washington State Ferries (WSF) is embarking on an initiative to enable its transition to an emission-free fleet by shifting its vessels to a hybrid-electric system. WSF is the largest ferry operator in the US, and the biggest contributor of greenhouse gas emissions of any state agency in Washington, burning 86Ml (23M gallons) of diesel fuel to transport 24M passengers every year. The 20-year programme to transition to an emission-free fleet is expected to cost $4bn over the period to 2040 and will involve building new ferries, converting existing vessels to hybrid-electric, and electrifying terminals to enable them to recharge. “For operations, the aim is that the vessels will rely on electric propulsion. The programme’s goal is to meet or exceed mandatory CO2 reduction targets of 40% by 2030, and 70% by 2040,” says Conrad. “We will be advising on the electrical engineering and power modelling as a subconsultant, as well as providing programme management services. It is a tremendously exciting project to be involved with because it will really raise the bar for sustainability in the ferry industry.”

Our commissioning processes and interface management and systems integration expertise are supporting Sound Transit’s in-house team

Serving a social purpose

This is potentially the largest light rail transit programme in the country, outstripping even the expansion of LA Metro. The scale of public investment places great responsibility on Sound Transit to make sure that its spending benefits the community it serves, on as many levels as possible. Client and consultant are well-aligned in their efforts to capture the wider benefits of expanding the public transportation network.

“It is an agency that always takes deep pride in social outcomes and environmental sustainability, even before those things were really taken seriously in this part of the country,” says Moises. “When I joined in 2013, it was already a big deal to incorporate sustainability, and equity and inclusion, into the design-criteria manual.

“Mott MacDonald continues to support Sound Transit in implementing what the agency has been trying to do for many years. But there’s always more to do. The agency is looking at diversity and inclusion beyond a checkmark or a percentage. And Mott MacDonald is looking to bring value to the client by really leveraging the small-business community, particularly businesses led by disadvantaged groups.”

187km

(116 miles)

Planned length of the light rail network in 2040

32km

(20 miles)

Network in 2008

Project

Sound Transit ST2 and ST3

Client

Sound Transit

Location

Seattle, Washington, USA

Expertise (rail systems construction management):

Rail systems engineering, construction oversight and inspection services, systems integration, interface management project controls, cost engineering

Expertise (design-build project management):

Design-build contract and project management, commercial, cost and schedule management, construction oversight, geotechnical, infrastructure, and structural construction oversight and monitoring, systems construction, rail systems design oversight and review, management of interfaces with authorities

Sound Transit know that to to deliver projects, they need more expertise in Seattle. In London, for example, there are thousands of people working for Network Rail and Transport for London. It is challenging for a new agency to build that from scratch. As an international consultant, we have that resource and expertise.''

Conrad Fawcett, divisional general manager, Mott MacDonald

Mott MacDonald has thoughtfully and slowly built a case for supporting the agency in asset management, not just jumping in, trying to make a buck, but really discerning if they can provide a qualified offering.''

Moises Gutierrez, chief system quality officer, Sound Transit