Chinese contractors vs others: Why Rironi-Mau Summit is ahead of Nairobi-Mombasa road dualling

Kenya’s ambitious road expansion programme is producing two contrasting stories. While construction is visibly advancing on the Rironi-Mau Summit Highway, plans to expand the Nairobi-Mombasa road remain at the restructuring and procurement stage, raising questions about why one project has moved from planning to construction while the other is still seeking an investor.

The contrast has drawn attention to the role of Chinese contractors in Kenya’s infrastructure development, particularly after two Chinese companies secured contracts to upgrade the Rironi-Mau Summit corridor.

However, the difference between the projects is not simply that Chinese contractors are building one road while non-Chinese firms are associated with the other. Their financing arrangements, procurement histories, project designs and stages of implementation are significantly different.

The Rironi-Mau Summit project has already secured two concessionaires, reached financial and contractual arrangements and commenced construction. By comparison, the Nairobi-Mombasa project underwent a major redesign after the government rejected an earlier privately initiated proposal and restarted the process.

That distinction helps explain why the two projects are moving at different speeds.

The 233-kilometre Rironi-Nakuru-Mau Summit highway programme was officially launched by President William Ruto on November 28, 2025.

It is being implemented through two Public-Private Partnership (PPP) arrangements involving China Road and Bridge Corporation (CRBC), Kenya’s National Social Security Fund (NSSF), and Shandong Hi-Speed Road and Bridge International.

The project was divided into two main components.

CRBC, working with NSSF, is responsible for the approximately 139-kilometre first phase covering the Rironi-Naivasha-Gilgil section and the Rironi-Mai Mahiu-Naivasha road.

The component was launched at an estimated cost of US$863 million, with the concessionaire expected to finance, construct, operate and maintain the road before handing it back to the government.

The second component, covering approximately 94 kilometres between Gilgil, Nakuru and Mau Summit, was assigned to Shandong Hi-Speed Road and Bridge International at an estimated cost of US$678.56 million.

Together, the two components form a continuous upgraded corridor linking Nairobi to the Rift Valley and western Kenya.

The decision to use two Chinese concessionaires was partly driven by financing and approval timelines.

Roads Principal Secretary Joseph Mbugua explained that the government had initially considered a single investor for the wider project. However, the financing requirement exceeded US$1 billion, which would have triggered additional approval processes in China and potentially delayed implementation.

Splitting the project into two components allowed the government to proceed with separate concession arrangements and bring the contractors on site sooner.

The approach was therefore not merely about choosing Chinese firms. It was also about restructuring the project to make financing and implementation more manageable.

One of the defining features of the Rironi-Mau Summit project is that the government secured private-sector partners before launching construction.

Instead of waiting for annual budget allocations to fund the entire undertaking, the PPP model brings together private investment and debt financing to pay for construction.

The CRBC-NSSF arrangement also introduced domestic institutional capital into the project, with the pension fund participating alongside the Chinese contractor.

The broader financing model is based on approximately 75 per cent debt and 25 per cent equity, with the concessionaires expected to recover their investment through toll revenue during the 28-year operating period after construction.

The arrangement shifts much of the initial financing burden away from direct government borrowing, although it does not eliminate public-sector obligations and risks. The government still has responsibilities relating to land, approvals, regulation, and other enabling infrastructure.

The project also benefits from having an established construction corridor. It largely involves upgrading existing roads rather than building an entirely new highway across a fresh alignment.

That reduces some of the challenges associated with acquiring extensive new land, although construction still requires managing traffic, relocating utilities and addressing environmental and engineering issues.

The government has also adopted a fast-track construction programme involving multiple work teams operating simultaneously along different sections.

In July 2026, KeNHA Director General Luka Kimeli reported that construction progress stood at approximately 15 per cent on the CRBC section and 10 per cent on the Shandong section.

The government subsequently reported that construction activity was advancing, with more than 90 teams deployed across the Rironi-Naivasha section.

However, the project has also encountered delays. On October 30, 2026, Transport Cabinet Secretary Davis Chirchir pushed the expected opening of the Rironi-Naivasha section from October to December after contractors failed to meet the earlier target.

The Nairobi-Mombasa highway expansion has followed a more complicated route.

The government initially considered a privately initiated proposal by US-based Everstrong Capital to construct a new 419-kilometre expressway alongside the existing highway.

The proposed project, estimated at approximately Ksh468 billion, was intended to improve movement between the Port of Mombasa and Nairobi through a separate high-capacity road.

However, the proposal encountered difficulties during the PPP approval process.

The Treasury’s PPP Committee rejected it in July 2025, citing concerns about its financial structure, technical capacity, and overall commercial viability.

One of the major challenges involved the proposed greenfield alignment, which would have required acquiring thousands of acres of land. The cost of land acquisition was expected to increase the overall project cost and potentially push toll charges higher.

The government also declined to provide some of the policy guarantees sought by the investor, including measures that would have compelled heavy commercial vehicles and long-distance buses to use the proposed toll road to guarantee traffic volumes.

The consortium subsequently faced another setback when Portuguese engineering firm Mota-Engil withdrew. Its departure weakened the consortium’s ability to demonstrate the technical and financial capacity required for the project.

Everstrong challenged the government’s decision before the PPP Petition Committee, but the tribunal dismissed the petition in April 2026, upholding the rejection.

The failure of the initial proposal meant that the government had to reconsider the entire project structure instead of proceeding directly to construction.

In July 2026, the government announced a major shift in the proposed Nairobi-Mombasa highway expansion.

Rather than constructing a completely new expressway, it would upgrade the existing 461-kilometre A8 highway from a two-lane road into a minimum four-lane, access-controlled toll road.

The Treasury’s PPP Directorate disclosed that the government had begun procuring a transaction adviser to review the project’s technical and financial feasibility and guide the search for a new private investor.

The adviser is expected to help determine the road’s technical design, financing structure, commercial model and procurement arrangements before the government invites bids from prospective investors.

The revised plan is intended to make greater use of the existing road reserve, reducing the extensive land acquisition requirements associated with the earlier proposal.

It is also expected to incorporate measures such as interchanges, service roads and controlled access points to preserve local connectivity while increasing the highway’s capacity.

However, as of the July 2026 report, the process was still at the transaction-adviser stage, meaning the project had not reached the point where a construction contractor could be mobilised.

This is the biggest immediate explanation for the difference in progress between the two highways.

Rironi-Mau Summit already has concessionaires implementing signed project arrangements, while Nairobi-Mombasa is still working towards a redesigned investment and procurement model.

The involvement of Chinese companies in the Rironi-Mau Summit has inevitably brought attention to China’s growing role in Kenya’s infrastructure sector.

CRBC has previously undertaken major projects in Kenya, including the Standard Gauge Railway, while Chinese construction companies have participated in several road and transport infrastructure developments across the country.

The Rironi-Mau Summit arrangement also marks a return to large-scale Chinese participation through a financing model that combines debt and equity rather than relying solely on conventional sovereign borrowing.

The two Chinese companies were expected to invest approximately US$1.5 billion in the highway expansion, with the financing structured around debt and equity and a 28-year toll concession.

But the Nairobi-Mombasa experience shows that the nationality of a proposed contractor does not, by itself, determine whether a project will succeed or fail.

The earlier Nairobi-Mombasa proposal involved an American investor and a consortium with international engineering partners. It was rejected because of concerns over its financing, technical capacity, land requirements, and commercial viability.

The subsequent redesign is now focused on finding a structure that can attract private investment while reducing the financial and land acquisition challenges.

The two projects are also not identical in their engineering requirements.

Rironi-Mau Summit is an upgrade of an existing transport corridor that combines four-lane and six-lane sections, grade-separated interchanges, bridges, underpasses, service roads and other safety features.

The design provides for additional capacity between Naivasha and Nakuru, where traffic volumes are particularly high, and an elevated section through Nakuru town to reduce congestion.

The Nairobi-Mombasa project, meanwhile, is being redesigned around expansion of the existing 461-kilometre highway into a minimum four-lane access-controlled toll road.

The revised approach is intended to reduce land acquisition and preserve local connectivity while improving the movement of long-distance traffic.

The projects therefore have different engineering and procurement demands, and their timelines cannot be compared solely by looking at the number of kilometres involved.