By Benadeta Mwaura - Reporter
Kenya, July 22, 2026 - Nairobi is edging closer to joining the ranks of global cities with underground rail systems after the Nairobi County Executive approved the first phase of a Mass Rapid Transit System (MRTS) that includes the capital's first underground railway beneath the Central Business District (CBD).
The approval marks a significant milestone in Kenya's long-running efforts to modernise public transport and tackle chronic traffic congestion that costs the economy billions of shillings annually through lost productivity, fuel consumption and delays.
The decision was made during the 90th Nairobi County Executive Committee meeting chaired by Governor Johnson Sakaja, with the project having been developed jointly with the Executive Office of the President as part of the Nairobi Metropolitan Mass Rapid Transit System (NMRTS).
Phase One of the project will consist of two flagship components, an underground transit corridor running beneath Nairobi's CBD and the Eastlands Line, designed to connect one of the city's most densely populated residential areas with the city centre.
Governor Sakaja described the approval as the beginning of implementation after years of planning.
"This marks the beginning of implementation after years of planning to address chronic traffic congestion," Sakaja said after the County Executive approved the framework.
Although detailed engineering designs and timelines are yet to be released publicly, officials say the underground section will serve as the central spine of an integrated transport network expected to link rail, Bus Rapid Transit (BRT), commuter rail and other public transport systems.
The underground rail proposal comes as Nairobi continues to pursue multiple transport projects aimed at reducing dependence on private vehicles and easing congestion.
The government is already financing the Nairobi Railway City project while Kenya Railways has separately unveiled plans to extend the Standard Gauge Railway (SGR) from Syokimau directly into Nairobi's CBD through a new 15-kilometre railway link, eliminating the current last-mile challenge faced by thousands of passengers.
The National Treasury has also committed billions of shillings towards upgrading the Riruta-Lenana-Ngong commuter railway line and supporting the Nairobi Railway City redevelopment programme.
Together, these projects signal a broader shift toward rail-based urban mobility as Nairobi's population continues to expand.
Unlike conventional commuter rail, underground metro systems operate independently of road traffic, allowing trains to maintain predictable schedules regardless of congestion above ground.
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Urban transport experts have long argued that Nairobi's rapidly growing population requires high-capacity transit capable of moving hundreds of thousands of commuters daily while reducing greenhouse gas emissions, improving air quality and lowering travel costs.
An underground system could also preserve limited surface road space while integrating with future BRT corridors, commuter rail services and non-motorised transport.
Despite the breakthrough, major questions remain over financing, construction costs and implementation timelines.
Globally, underground rail systems rank among the most expensive transport infrastructure projects because of tunnelling, utility relocation, land acquisition, specialised engineering and station construction. Studies show underground urban rail projects can cost significantly more than surface rail depending on geology, station density and engineering complexity.
County officials have yet to disclose the project's estimated cost, funding structure or commencement date.
If implemented successfully, Nairobi would become one of the few African cities with an underground urban rail network, joining a small group that includes Cairo while positioning Kenya's capital for future metropolitan growth.
For commuters who spend hours navigating daily traffic jams, the project represents more than another infrastructure announcement, it signals a potential transformation in how Nairobi moves people across one of Africa's fastest-growing urban economies.
Whether that vision becomes reality will now depend on securing financing, completing detailed designs and delivering one of Kenya's most ambitious urban transport projects.