Brazil’s First Immersed Tunnel to Link Santos and Guarujá in the Baixada Santista

Building Brazil’s first immersed tunnel is set to reshape mobility across the Baixada Santista in a genuinely novel way. This major piece of infrastructure will create a permanent connection between Santos and Guarujá, streamlining local travel with far greater efficiency.

How will the structure of the new immersed tunnel work?

The flagship scheme will join the two areas via a route totalling roughly 1.6 km. Within that, an 870-metre submerged section will run beneath the channel serving the busy Santos port, significantly modernising the regional link.

Once the works are complete, a journey that often takes an hour is expected to drop to under five minutes. Residents should see meaningful day-to-day improvements, including the key structural details and most relevant features outlined below.

• Three lanes: The design includes three traffic lanes in each direction for vehicles.
• Integrated tracks: A dedicated corridor will be fully prepared to accommodate the VLT (light rail).
• Active travel: The structure will include specific routes for pedestrians and cyclists.

What is the financial amount invested in the project?

The latest budget for the development is set at 6.8 billion reais. This substantial figure underlines the scale of the initiative, exceeding earlier government estimates that anticipated far lower spending to deliver this large public investment.

Public funding plans point to a balanced split of resources between state and federal levels. To ensure full transparency and strong governance, the port authority has set up an exclusive guarantee account to manage these essential funds.

How will environmental impacts be monitored in the area?

Large engineering works require strict oversight of multiple local ecological factors throughout delivery. São Paulo state’s environmental authority has already issued an important preliminary licence, but the future concessionaire will need to submit detailed ecological mitigation plans.

Environmental preservation

Critical monitoring points

The project calls for continuous supervision of dredging activities and for sediments removed from the channel to be handled correctly.

Noise impacts on the fauna and flora of the mangroves along the construction route will also be assessed.

Protecting local ecosystems will go hand in hand with effective communication programmes aimed directly at nearby residents. The winning company must ensure wildlife and protected areas remain safeguarded, in line with the criteria set out in the main environmental topics below.

• Detailed mapping of direct and indirect impacts on local mangroves.
• Structured programmes for ongoing dialogue with communities living in the area.
• Strict protective measures to minimise disturbance to regional wildlife.

What are the stages in the construction timetable?

The innovative construction approach will involve placing prefabricated concrete modules in sequence directly into the excavated channel bed. This advanced underwater engineering will require exceptionally tight scheduling to ensure operational success, supporting technological development across this important national sector.

Public plans indicate steady progress with clear deadlines for each essential phase of the transport project. Official projections set out the annual targets defined by managers, showing the time-based evolution of the logistics infrastructure as detailed below.

• The year 2026 is reserved for initial preparation of the technical design.
• The official start of the first structural works is scheduled for 2027.
• Specialist production of concrete blocks and final assembly will run through to 2031.

What will be the future socio-economic impacts of the project?

Mota-Engil won the tender and has taken on responsibility for building and maintaining the route for 30 years. The agreement is expected to provide technical stability for operating the transport complex, directly benefiting users across São Paulo’s coastal region.

Beyond the substantial time savings, delivering this infrastructure megaproject is expected to create thousands of direct and indirect jobs locally. This surge in opportunities should stimulate the economy of the port cities, while providing a cleaner, faster and extremely safe crossing for workers and other travellers.