The Portuguese construction group Mota-Engil won the auction for the Santos-Guarujá Tunnel under a public-private partnership (PPP) in São Paulo. 

The project is valued at approximately BRL6.8 billion (US$1.2 billion), with around BRL5.14 billion (US$952 million) to be borne jointly by the Federal and São Paulo State governments, and the rest supplied by the private operator. The contract is for 30 years, during which Mota-Engil will be responsible for building, operating, and maintaining the tunnel. The tunnel will be 1.5 km long, with 870 meters immersed, built from pre-cast concrete segments installed on the seabed of the port channel — a technique widely used in Europe and Asia. The infrastructure will feature three lanes in each direction, one of which will be reserved for a Light Rail Vehicle (LRV), as well as pedestrian and bicycle crossings and a utility gallery. The multimodal design positions Baixada Santista at the forefront of future mobility, offering faster, more sustainable, and more inclusive transport solutions.

Currently, the connection between Santos and Guarujá is primarily made by ferries, which take an average of 18 minutes per crossing but can reach up to 1 hour due to queues and operational constraints. By road, travel time is also about 1 hour. With the tunnel, the journey will take just 5 minutes, directly benefiting more than 2 million residents of Baixada Santista and thousands of workers who commute daily between the cities. The decision to use the immersed tunnel technique followed a detailed technical assessment. Options like a bridge or bored tunnel were ruled out due to constraints from Santos Air Base, the intense maritime traffic in the port channel, and the area’s unstable soil conditions. The immersed approach offers advantages such as reduced urban and environmental impacts, minimal expropriations, and quicker, safer construction.