The Kenya National Highways Authority (KeNHA) has confirmed that the consortium of China Road and Bridge Corporation (CRBC) and the National Social Security Fund (NSSF) has been selected as the Preferred Proponent for the Nairobi–Nakuru–Mau Summit and Nairobi–Mai Mahiu (A8 South) Road projects.

According to a disclosure by KeNHA, the project will be implemented under a Public-Private Partnership (PPP) model, covering approximately 175 kilometres from Rironi in Kiambu County to Mau Summit in Nakuru County, and an additional 58 kilometres of the Nairobi–Mai Mahiu (A8 South) section.

In a notice dated October 9, 2025, KeNHA stated that the PPP Committee, National Treasury, and Economic Planning had approved the project after determining that it met “the public interest, value for money, private party suitability, project feasibility, bankability, and affordability criteria.”

Road to Feature Toll Stations and Interchanges

The KSh200 billion four-lane expressway will feature eight toll stations, 15 interchanges, 25 kilometres of service lanes, eight wildlife crossings, 41 U-turns, 41 underpasses, and 118 bus bays, according to details from the project proposal.

Motorists will pay a base toll rate of Ksh8 per kilometre, with a 1 percent annual increase to account for inflation and exchange rate fluctuations.

“Based on comparative assessment, the Evaluation Committee concluded that China Road & Bridge Corporation (CRBC) & National Social Security Fund Trustees (NSSF) align with the Contracting Authority’s Output Specifications and PPP Act Cap 430 requirements with a proposed toll rate of Ksh 8 per kilometre with a 1 percent escalation rate per annum,” part of the KeNHA notice read.

The open tolling system will allow motorists to pay for only the distance travelled, making it a first of its kind on a Kenyan highway.

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Project Implementation and Impact

The expressway will traverse the counties of Kiambu, Nyandarua, and Nakuru, significantly improving connectivity between Nairobi and western Kenya.

KeNHA Director General, Eng. Luka Kimeli said the authority welcomes public feedback on the project and assured that all legal, financial, and environmental requirements have been fulfilled before commencement.

Construction is expected to begin before January 2026 and take two years to complete. The expressway will operate under a 30-year concession, after which ownership will revert to the government.

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KeNHA noted that the project proponents had submitted feasibility study reports in September 2025, after which the PPP Committee endorsed the CRBC–NSSF proposal as compliant with the PPP Act.

“The approval marks a major milestone in the government’s plan to deliver modern and efficient infrastructure through private investment partnerships,” the statement added.

Once completed, the Rironi–Mau Summit expressway is expected to decongest the busy Nairobi–Nakuru highway, cut travel time by nearly half, and promote trade and tourism across the corridor.

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A picture of the KeNHA Boss Engineer Luka Kimeli
Photo courtesy/X