Ground surveys launch São Paulo metro Line 22 push

Ground surveys have begun in Cotia for São Paulo’s planned Line 22-Brown, marking the first visible field phase for a metro project designed to link Cotia and Osasco to the capital’s existing network.

Fieldwork begins on Cotia section of Line 22

Recent updates from São Paulo’s metro authorities and regional news outlets indicate that contractors have moved drilling rigs and technical teams into Cotia to carry out soil investigations for Line 22-Brown. The first boreholes were reported in and around the city’s sports complex area, signaling that the project has shifted from purely desk-based studies to on-the-ground verification.

The work focuses on geotechnical sondagens, or borehole drilling, which will map soil layers, groundwater conditions and potential geological constraints along the future alignment. These campaigns are a standard early stage in Brazilian rail projects, feeding essential data into engineering designs for tunnels, stations and ventilation shafts.

Publicly available information shows that this first wave of surveys is concentrated in western Cotia, near key road junctions that connect residential neighborhoods to the regional highway network. As crews test different points along the corridor, planners are expected to refine construction methods and adjust the technical scope of structures such as shafts, cut-and-cover segments and deep stations.

Reports from local coverage underscore that these sondagens are still limited in scale but symbolically significant for residents, many of whom have followed Line 22 discussions for years. Visible drilling equipment and fenced-off test sites represent the most tangible evidence to date that the long-discussed project is progressing.

From feasibility approvals to on-the-ground surveys

The launch of field surveys follows a sequence of institutional milestones for Line 22 in recent months. State heritage body deliberations have resulted in a favorable opinion on the project’s overall viability, subject to conditions that seek to protect historically sensitive areas along the alignment between São Paulo, Osasco and Cotia.

In parallel, environmental documentation advanced with the publication of an updated impact assessment tailored to the corridor. That material outlines projected changes in noise, vibration and urban form, as well as mitigation measures for natural and built environments. The transition from paper-based studies to physical drilling suggests that preliminary analyses were considered robust enough to justify detailed design work.

Market and demand studies have also moved ahead. Specialized consultancies have been selected through competitive bidding to deepen forecasts on passenger flows, potential fare revenues and broader economic impacts. These inputs are expected to inform decisions on whether the line will follow a traditional public works model or a public-private partnership structure, a choice that will influence future procurement schedules.

According to public reports, São Paulo’s metro company has already completed an initial engineering concept for Line 22, which frames station locations, tunnel profiles and integration points with other lines. The newly started ground campaigns are designed to verify and refine those assumptions so that more precise construction documents and cost estimates can be prepared.

What the new line could mean for commuters

Planning documents and open data from the metro system describe Line 22-Brown as a transversal corridor intended to connect predominantly residential zones in Cotia and Osasco to existing hubs in São Paulo’s western region. The route under study would link to Line 2-Green at Sumaré station, providing passengers from the outskirts with a direct rail path into central neighborhoods and onward transfers to other metro and rail services.

Preliminary demand modeling cited in recent analyses suggests that Line 22 could move several hundred thousand passengers a day once fully operational, with a substantial share representing people who do not currently use rail. Analysts note that the corridor today depends heavily on buses and private vehicles, particularly along the often-congested Raposo Tavares highway.

Travel-news observers point out that a fully built Line 22 could reshape commuting patterns by offering a time-competitive alternative to road travel at peak hours. Faster, more predictable journeys between Cotia, Osasco and central São Paulo would be especially relevant for workers with so-called pendular travel patterns, who move daily from residential outskirts toward job clusters closer to the city’s core.

The line is also expected to play a role in easing pressure on existing east-west routes and bus corridors. As more riders shift from road-based modes to high-capacity rail, forecasts indicate potential reductions in congestion and emissions along the western approach to São Paulo, though the scale of that impact will depend on the final service pattern and ridership levels.

Technical and heritage conditions still shape the project

Despite the concrete step represented by ground surveys, Line 22 remains in a pre-construction phase, and several technical and regulatory hurdles must still be addressed. Heritage authorities have attached conditions to their favorable opinions, including requirements for monitoring impacts on protected buildings, archaeological assets and culturally significant landscapes along the route.

Engineering teams will need to incorporate those constraints into final designs, adjusting tunnel depths, station accesses and emergency structures to avoid or minimize interference with sensitive sites. This process can lead to alignment tweaks, redesign of ventilation shafts and modified construction methods in complex segments.

Environmental regulators are also expected to scrutinize how excavation, spoil transport and construction staging will be handled in dense urban surroundings. Issues such as vibration limits, noise mitigation and temporary traffic changes during works are usually defined in greater detail later in the design cycle, informed in part by the new soil and groundwater data now being gathered.

Observers of São Paulo’s infrastructure pipeline note that such conditions are typical for large urban rail projects and do not necessarily signal unusual obstacles. However, they add time and complexity to the schedule, making early-stage field information especially valuable for anticipating risks and cost pressures.

Next steps and broader metro expansion context

With field investigations underway, the next visible milestones for Line 22 are expected to include expanded survey fronts, completion of detailed geotechnical reports and potential publication of updated route diagrams. These steps will feed into the drafting of executive designs and, later, bids for major civil works and systems contracts, depending on what delivery model the state ultimately selects.

The project forms part of a broader wave of metro and urban rail expansion in the São Paulo region, which includes ongoing construction on other lines and planning for additional corridors intended to close gaps in the network. Together, these initiatives reflect an effort to bring high-capacity transit closer to communities in the metropolitan periphery.

Analysts following the sector highlight that the timeline from early sondagens to full passenger service can span many years, particularly when projects cross multiple municipalities and require complex permitting. Nonetheless, the appearance of drilling teams in Cotia marks a tangible progression from abstract plans to measurable actions on the ground.

For travelers and residents watching the project’s trajectory, the start of ground surveys offers an early indicator that Line 22-Brown is beginning to move from concept toward implementation, even as critical decisions on financing, phasing and final design remain ahead.