TransportationCentral Subway
A 3.1-mile underground extension of the Market Street subway, delivering twin bored tunnels, three underground stations and a cavern beneath an operating city centre.
View project
Seattle Climate Pledge Arena Tunnel
Pedestrian and service tunnels delivering a new arena beneath a dense downtown block.
Pedestrian, service and loading tunnels integrated with a major venue conversion.
Tunnel design, waterproofing and construction phase services delivered alongside a live urban construction programme and heavy public access.
Scope of work
- Tunnels & Underground Engineering
- Civil & Architectural Design
Project facts
- Type
- Pedestrian + service
- Setting
- Urban core
- Programme
- 2018–2021
- Completion
- 2021
More transportation projects
TransportationCentral Subway project details
TransportationNorthgate Link Extension
A 4.4-mile light rail extension including two cut-and-cover stations, a cut-and-cover crossover and 2.5 miles of underground guideway.
View project
TransportationSydney Metro City & Southwest
Metro-scale station caverns and twin running tunnels on Australia’s largest urban rail programme.
View project
TransportationCaldecott Improvement Project
A four-bore highway tunnel through the Oakland Hills, including a 3.5-mile bore and seismic retrofit.
View project
TransportationSR 99 Alaskan Way Viaduct Replacement
A four-lane, four-block downtown viaduct built as a structurally independent tunnel beneath a working street.
View project
TransportationCoos Bay Rail Tunnel Rehabilitation
Rehabilitation and rock-lining repair of six miles of historic single-track rail tunnel in basalt.
View project
Planning something underground?
Every project starts with a conversation about your ground, your constraints, and your programme.