Mexico City Plans MX$40 Billion Metro Line 3 Overhaul

Mexico City will modernize Metro Line 3 through a MX$40 billion coinvestment project covering 45 new trains, tracks, stations, and control systems, with major works scheduled to begin in 2027.

Mexico City will invest more than MX$40 billion (US$2.25 billion) to modernize Metro Line 3, including the acquisition of 45 trains, the replacement of tracks, and the renovation of all 21 stations. Major construction will begin in 2027, while authorities pledged that no stations will close during 2026.

The project will renovate one of the capital’s most important transit corridors, which extends about 23km from Indios Verdes to Universidad and connects northern Mexico City with central and southern districts. The line carries more than 1 million passengers per day and recorded about 175 million trips during 2025, according to the city government.

Mexico City Mayor Clara Brugada says the project will address almost five decades of infrastructure deterioration and operational challenges. Line 3’s first section opened in 1970, while its current route was completed in 1983. “Once the work on Lines 1 and 2 is completed, we will begin the comprehensive transformation of Metro Line 3,” says Brugada. She adds that the administration’s modernization strategy will cover the Metro network’s three oldest and busiest lines.

New Trains, Tracks, and Control Systems

The modernization program will focus on rolling stock, tracks, electrical and electromechanical infrastructure, train control systems, and station facilities. Authorities plan to purchase 45 new trains equipped with updated technology to replace the units currently operating on the line. The track system will undergo a complete rehabilitation, including rail replacement and corrective works in areas affected by differential land subsidence and uneven track levels.

Mexico City’s sinking ground has affected transport and utility infrastructure across several areas of the capital. On Line 3, authorities expect the correction of uneven sections to improve passenger safety and comfort, reduce interruptions, and allow trains to operate at more consistent speeds.

The project also covers the modernization of electrical, electromechanical, telecommunications, and fire-protection systems. A communications-based train control system, known as CBTC, will replace the existing train control and signaling infrastructure.

CBTC technology allows operators to monitor train locations more precisely, helping reduce the required distance between trains and potentially increasing service frequency. The system is also expected to strengthen operational safety and efficiency.

All 21 stations will be renovated, with improvements focused on accessibility, lighting, escalators, elevators, surveillance systems, passenger circulation, and public spaces. The line currently provides seven transfers to other Metro lines and 13 connections to the Metrobús network.

The Universidad terminal has already been renovated as the first visible stage of the project. Work at the station included the rehabilitation of roofs, flooring, stairs, wall finishes, and metal structures, alongside the installation of about 1,500 LED lights and electronic access gates.

Project Builds on Mexico City’s Metro Investment Strategy

The Line 3 overhaul follows a broader Metro investment and modernization strategy outlined by Mexico City during the approval of its 2025 Economic Package. The package included a historic MX$23 billion allocation for the Collective Transportation System, known as STC Metro. Brugada identified the network as a priority for her six-year administration, announcing that studies would be conducted during the first half of 2025 to develop the basic engineering required to renovate Line 3 and secure financing for the project. 

The 2025 budget also contemplated the installation of 5,000 video surveillance cameras throughout the Metro network and the creation of a new Command and Control Center, or C2. Additional commitments included the modernization of elevators and escalators and the rehabilitation of station facades and floors.

Those measures formed part of a wider mobility package that allocated MX$6.95 billion to mobility and electromobility projects, including three new Cablebús lines, a Metrobús route along Circuito Interior, Ecobici expansion, microbus replacement, and public transportation modernization.

The Line 3 announcement represents the transition from the planning and basic-engineering phase presented in the 2025 budget to a defined comprehensive project with an investment exceeding MX$40 billion.

MBN reported in January 2025 that STC had issued several tenders for the modernization of the Metro, including a basic-engineering contract covering Line 3 from the Ticoman workshops to the Universidad depot. The contract incorporated infrastructure assessments, conceptual designs, geospatial engineering, and Building Information Modeling methodology.

Those tenders also covered works on Lines 1 and 9, upgrades to maintenance facilities, rehabilitation of the PCC-II operational control center, roof replacement, and measures to mitigate leaks and flooding throughout the network.

Major Works to Start in 2027

During 2026, the government will focus on the bidding process, technical studies, equipment manufacturing, workshop preparation, and preliminary work that will not require station closures. Brugada emphasized that no Line 3 stations will close and service will not be interrupted during the remainder of 2026.

More disruptive construction, including track replacement, is expected to begin in 2027. Instead of fully closing long sections for extended periods, as occurred during the modernization of Line 1, authorities plan to prioritize overnight work, weekend interventions, and temporary closures organized by section.

“The idea is not to close the Metro, but to intervene during specific hours, weekends, and only on the days when it is necessary,” says Brugada. Authorities have not ruled out limited service interruptions after 2026, but said passengers will be provided with alternative transportation whenever closures are required.

The selection process for the project operator will be conducted under a coinvestment model established in Mexico City legislation. The city published the project’s technical guidelines in the Official Gazette of Mexico City, opening a competitive process to identify a company with the technical and financial capacity to execute the modernization.

Interested companies have until July 20 to register, while proposals are scheduled to be submitted by Aug. 31. Authorities expect to announce the selected participant on Sept. 14.

Juan Pablo de Botton, Minister of Administration and Finance of Mexico City says the financing structure could reduce the project’s financial costs by more than half. Any long-term financial obligations will require approval from the Mexico City Congress and will be subject to transparency and accountability requirements.

Despite the size of the investment, Brugada said the project will not result in an increase to the Metro’s MX$5 fare.