With over 125 years of experience, WSP has expertise in all forms of transport tunnels, including work for the roads and highway, rail, transit, and aviation industries.



With the growth of urban populations, the increase in number and size of mega cities, and reverse migration to cities, tunnels are more frequently the answer to congestion problems. WSP is the forerunner in transportation tunnels, whether it be road tunnels under cities for cars to bypass the ensnarement of the downtown core, or rail and metro tunnels that offer commuters an alternative to cars.

Tunnel Experts at Work

At WSP, we are dedicated to helping our clients find the best solutions to improve the transportation options that they currently offer. When the answer is located underground, we back up our expertise with over 130 years of experience, dating back to the construction of the first segment of the New York Subway system in 1904. Ever since, we have been committed to working with our clients to identify the best methods for their specific project, to best meet their schedules, budgets, and any other constraints the location might present. We are known globally for our innovative approaches and state-of- the-art, creative solutions to underground transportation projects in the rail, transit, roads, or aviation sectors.

Transportation tunnels are often necessarily built in the densest urban centres to help relieve the very density that complicates their construction. WSP employs experts across all aspects of tunnelling practices to ensure that we have the expertise on hand to confront even the most complex or intensive projects. Our global presence means that you can draw on our experience worldwide, across various ground conditions – whether soft ground, hard rock, or mixed-face – in big cities, active seismic areas, mountain passes, and under bodies of water. Our local offices ensure that you are dealing with professionals who are experienced with the specificities unique to your corner of the world, offering solutions that are individualized for your local situation, politics, and site specifications.

Follo Line Rail Tunnel TBM

Follo Line, Oslo, Norway

Full Lifecycle Services

We provide comprehensive services for every aspect of the construction of your tunnels and underground project, including ground investigation, tunnel design, ground improvement, initial and final support, instrumentation and monitoring, tunnel systems, and ventilation/fire life safety aspects.

Furthermore, we also have the expertise to provide support across the entire project, from design, to construction management, to testing and commissioning. We also provide condition assessment, rehabilitation, re-purposing and upgrading of tunnels and underground transportation facilities.

Tunnels begin with Ground Investigation, because accurate surveys are the best way to prevent surprises and delays later down the road. Our geotechnical experts have dedicated years not only to the practice, but also research in order to continuously build upon our understanding of ground behavior when excavated.

The result is an unparalleled breadth of acumen that continues to improve our ability to construct underground facilities without disturbing existing facilities and utilities and to ensure that our work doesn’t impact the surrounding area.

Technology-Driven Design

Our design team works extensively with the latest technology such as numerical modeling of ground/structure interaction, as well as BIM and VDC, to perfect schematics in virtual reality, allowing problems to be rectified before ground is broken and reducing the likelihood of surprises arising during construction that could cause delays, extra costs, or damage to surrounding structures.

Our wide-ranging expertise in rail, roads, and aviation means that we understand transportation tunnels from all sides of the project, providing a holistic approach to their design and construction.

Rail and Transit Tunnels

WSP has managed large complex tunneling projects, set records in designing TBM-driven tunnels, and has engineered tunnels that are exceptionally deep, large in diameter and set in challenging ground conditions. We regularly advise transit agencies on the increasingly critical issues of tunnel safety and security, vulnerability assessment, durability, sustainability, and risk management.

Road and Highway Tunnels

Whether threading tunnels under busy city streets, or boring through mountainous terrain, we are experienced in designing and managing a variety of construction techniques, including conventional drill-and-blast excavation, soft ground or hard rock tunnel boring machines.

We are also experienced in the use of specialized techniques like soft-ground or hard-rock sequential excavation, and immersed tube technology. Our projects have involved some of the most challenging ground conditions, high water pressures, and seismic or environmental conditions.

We designed the Alaskan Way Viaduct Replacement in Seattle, the largest diameter tunnel in the world, and recently completed construction of the Eurasia Tube in Istanbul, one of the deepest underwater tunnels in the world. 

Eurasia Tunnel

Eurasia Tunnel, Istanbul, Turkey

Aviation Tunnels

Tunnels play diverse roles in aviation, starting with the roads and trains that bring passengers to the airport. Larger airports also use tunnels for their own inter-terminal transit systems to help speed the flow of passengers between gates so they don’t miss their connections. Other tunnels transport luggage within the terminals for the same purpose. Recent examples include baggage and people-mover tunnels in John F. Kennedy International Airport in New York City, Dulles International Airport in Washington DC, and Hartsfield-Jackson Atlanta International Airport.

After the Ribbon is Cut

Once the tunnel is operational, we provide the following services:

With the growth of urban populations, the increase in number and size of mega cities, and reverse migration to cities, tunnels are more frequently the answer to congestion problems. WSP is the forerunner in transportation tunnels, whether it be road tunnels under cities for cars to bypass the ensnarement of the downtown core, or rail and metro tunnels that offer commuters an alternative to cars.

Tunnel Experts at Work

At WSP, we are dedicated to helping our clients find the best solutions to improve the transportation options that they currently offer. When the answer is located underground, we back up our expertise with over 130 years of experience, dating back to the construction of the first segment of the New York Subway system in 1904. Ever since, we have been committed to working with our clients to identify the best methods for their specific project, to best meet their schedules, budgets, and any other constraints the location might present. We are known globally for our innovative approaches and state-of- the-art, creative solutions to underground transportation projects in the rail, transit, roads, or aviation sectors.

Transportation tunnels are often necessarily built in the densest urban centres to help relieve the very density that complicates their construction. WSP employs experts across all aspects of tunnelling practices to ensure that we have the expertise on hand to confront even the most complex or intensive projects. Our global presence means that you can draw on our experience worldwide, across various ground conditions – whether soft ground, hard rock, or mixed-face – in big cities, active seismic areas, mountain passes, and under bodies of water. Our local offices ensure that you are dealing with professionals who are experienced with the specificities unique to your corner of the world, offering solutions that are individualized for your local situation, politics, and site specifications.

Full Lifecycle Services

We provide comprehensive services for every aspect of the construction of your tunnels and underground project, including ground investigation, tunnel design, ground improvement, initial and final support, instrumentation and monitoring, tunnel systems, and ventilation/fire life safety aspects.

Furthermore, we also have the expertise to provide support across the entire project, from design, to construction management, to testing and commissioning. We also provide condition assessment, rehabilitation, re-purposing and upgrading of tunnels and underground transportation facilities.

Tunnels begin with Ground Investigation, because accurate surveys are the best way to prevent surprises and delays later down the road. Our geotechnical experts have dedicated years not only to the practice, but also research in order to continuously build upon our understanding of ground behavior when excavated.

The result is an unparalleled breadth of acumen that continues to improve our ability to construct underground facilities without disturbing existing facilities and utilities and to ensure that our work doesn’t impact the surrounding area.

Technology-Driven Design

Our design team works extensively with the latest technology such as numerical modeling of ground/structure interaction, as well as BIM and VDC, to perfect schematics in virtual reality, allowing problems to be rectified before ground is broken and reducing the likelihood of surprises arising during construction that could cause delays, extra costs, or damage to surrounding structures.

Our wide-ranging expertise in rail, roads, and aviation means that we understand transportation tunnels from all sides of the project, providing a holistic approach to their design and construction.

Rail and Transit Tunnels

WSP has managed large complex tunneling projects, set records in designing TBM-driven tunnels, and has engineered tunnels that are exceptionally deep, large in diameter and set in challenging ground conditions. We regularly advise transit agencies on the increasingly critical issues of tunnel safety and security, vulnerability assessment, durability, sustainability, and risk management.

Road and Highway Tunnels

Whether threading tunnels under busy city streets, or boring through mountainous terrain, we are experienced in designing and managing a variety of construction techniques, including conventional drill-and-blast excavation, soft ground or hard rock tunnel boring machines.

We are also experienced in the use of specialized techniques like soft-ground or hard-rock sequential excavation, and immersed tube technology. Our projects have involved some of the most challenging ground conditions, high water pressures, and seismic or environmental conditions.

We designed the Alaskan Way Viaduct Replacement in Seattle, the largest diameter tunnel in the world, and recently completed construction of the Eurasia Tube in Istanbul, one of the deepest underwater tunnels in the world.