Transportation
São Paulo Signs $1.2B P3 for Brazil’s First Immersed Tunnel
Contract launches Santos–Guarujá port crossing under 30-year concession
An aerial view shows the port channel between Santos and Guarujá, where São Paulo state plans to build Brazil’s first immersed tunnel beneath one of Latin America’s busiest port corridors.
The state of São Paulo announced a public-private partnership with Portugal-based Mota-Engil to build Brazil’s first immersed tunnel, launching construction of a fixed link between the coastal cities of Santos and Guarujá and moving a roughly $1.2-billion transportation megaproject into execution.
The Santos–Guarujá Tunnel, an 870-m underwater crossing beneath the port channel serving the Port of Santos, will be delivered under a 30-year P3 covering design, construction, operation and maintenance.
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“What was impossible and expected for 100 years, we are going to make possible,” Rafael Benini, São Paulo’s secretary for investment partnerships, said in a statement following the signing. Benini said the project is now moving into design, with construction scheduled to begin next year.
Under the contract, the tunnel will carry three lanes of traffic in each direction, with a dedicated walkway for pedestrians and cyclists, plus a service gallery for utilities and systems. State officials estimate the crossing will cut travel time between Santos and Guarujá to less than five minutes, compared to trips of up to an hour by road or ferry, which are often affected by port traffic and weather conditions.
Immersed Tunnel Method Concentrates Marine Construction Risk
While immersed tunnels are common in Europe and Asia, they are relatively rare in the rest of the world compared to bored tunnels or bridges. This is mainly due to the complexity of marine construction, with risks related to dredging precision, buoyancy control during immersion and the tolerances needed to ensure watertight joints.
A project map shows the planned alignment of the Santos–Guarujá immersed tunnel and approach roads beneath the port channel linking the cities of Santos and Guarujá, including connections to surrounding urban and port infrastructure.
Map courtesy of the Government of São Paulo
State planners have said the immersed tunnel approach was selected to avoid navigation conflicts, height restrictions and surface disruption that a bridge or bored tunnel would have created within the Port of Santos corridor.
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The Santos–Guarujá project will require extensive dredging beneath an active shipping channel, construction of a dry dock for precasting massive concrete elements and tightly sequenced immersion and assembly operations coordinated with port activity. The works will be carried out beneath the access channel to the Port of Santos, requiring coordination with ongoing vessel traffic and port operations during construction.
Under the delivery plan outlined by the state, the tunnel will be built from a series of large reinforced-concrete elements fabricated in a purpose-built dry dock, sealed and fitted out before being floated into position, sunk into a prepared trench and connected underwater.
Once aligned, the elements will be joined using watertight seals, after which the structure will be backfilled and protected, locking in final geometry before internal systems installation begins.
Unlike bored tunnels, where alignment corrections can be made progressively, immersed tunnel installation allows limited opportunity for adjustment once immersion is underway, placing a premium on upfront engineering, marine surveying and construction sequencing.
P3 Extends Engineering Focus Into Operations
Beyond structural works, the project’s engineering scope extends into long-term operational systems embedded within the service gallery, including ventilation, drainage, fire and life-safety systems, power and communications infrastructure and continuous structural and environmental monitoring.
A rendering depicting the ingress to the tunnel that is intended to ease congestion and improve freight and commuter mobility between the two cities.
Rendering courtesy of Bnamericas
Because the P3 bundles construction with three decades of operation and maintenance, officials said systems will be designed for durability, access and maintainability over the concession term.
Mota-Engil won the concession in a September 2025 auction, offering a 0.5% discount on the maximum annual public payment. The project includes approximately $971 million in public contributions, split evenly between the São Paulo state government and the federal government, according to project documents.
São Paulo Gov. Tarcísio de Freitas said the signing marks a turning point for a project that has stalled repeatedly over the past century.
“The land connection between Santos and Guarujá is a dream that has been around for a hundred years and is finally becoming a reality,” he said in remarks released by the state. He added that the tunnel is expected to be completed and open to traffic in 2031.
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The project has already obtained a preliminary environmental license from São Paulo state's environmental agency, Cetesb, and is moving into detailed design and preparatory work. The review assessed impacts on mangroves, flora and fauna, noise and required expropriations, and sets conditions to be addressed during subsequent licensing.
The state’s published execution schedule shows 2026 will focus on design and related studies, with construction slated to begin in 2027 with site mobilization, dry dock construction and initial dredging.
Precasting of the tunnel’s concrete elements is planned for 2028, followed by immersion and assembly in 2029. Systems installation, testing and commissioning are scheduled for 2030 ahead of commercial operation the following year.
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Túnel | Brazil’s Official Website
The concession also includes road works in both Santos and Guarujá to integrate the new crossing into dense urban traffic networks on either side of the channel, with oversight by São Paulo’s transportation regulatory agency, Artesp.
State officials estimate the project will generate about 9,000 direct and indirect jobs while easing congestion in the Baixada Santista region and improving access to port-related employment and logistics corridors.
Benini said the next immediate step is to define the concrete tunnel module fabrication site. “The signing of the contract represents a decisive step toward transforming this project into reality, with direct gains for mobility, logistics and the quality of life of the population,” he said.
Bryan Gottlieb is the online editor at Engineering News-Record (ENR).
Gottlieb is a five-time Society of Professional Journalists Excellence in Journalism award winner with more than a decade of experience covering business, construction and community issues, including finance, law and real estate. He has reported for Adweek and the San Diego Daily Transcript and led a community newsroom in Santa Monica, Calif. He served as editor-in-chief of the Detroit Metro Times and as managing editor at Roofing Contractor, where he helped shape national industry coverage. At Engineering News-Record, Gottlieb covers breaking news, large-scale infrastructure and megaprojects, regulatory developments and business trends across the U.S. and global construction sectors.
email: gottliebb@enr.com | office: (248) 786-1591
