Private Investor Could Take Over Nairobi-Mombasa Highway Under New KeNHA Plan

Kenya has taken another step towards bringing private investment into the Nairobi-Mombasa Highway, with the Kenya National Highways Authority (KeNHA) beginning the process of preparing the road for a public-private partnership (PPP).

KeNHA is seeking a consultant to undertake feasibility studies and provide transaction advisory services for the proposed PPP. The work will determine whether the project is viable and how the partnership should be structured before a private partner is selected.

The consultancy is expected to take 15 months, comprising six months for feasibility studies and nine months for transaction advisory services. This means the government is still at the preparation stage rather than having reached the point of awarding the highway to a private operator.

The move follows a change in approach to the long-running plan to improve the Nairobi-Mombasa transport corridor. Instead of pursuing the previously proposed new expressway, the government has resolved to expand the existing highway.

The current plan involves increasing the capacity of the approximately 461-kilometre Nairobi-Mombasa Highway to at least four lanes and converting it into an access-controlled toll road.

The proposed investment has previously been estimated at about Sh466.8 billion. The upgraded road is expected to include controlled access points and tolling infrastructure, with the aim of improving traffic flow and safety along one of Kenya's most important transport corridors.

The development follows the collapse of the separate Sh468 billion proposal by US infrastructure investment firm Everstrong Capital to build a new Nairobi-Mombasa Expressway, dubbed Usahihi Expressway.

That proposal involved a new four-to-six-lane expressway, but the PPP process encountered challenges over affordability, public interest and the structure of the proposed project. The PPP Committee rejected the earlier Project Development Report in 2025.

The government subsequently directed KeNHA to focus on expanding the existing Nairobi-Mombasa Highway rather than pursuing the proposed greenfield alignment.

This latest approach could allow the government to use an existing transport corridor while introducing private capital for major capacity improvements, instead of developing an entirely new road corridor.

The highway forms part of the Northern Corridor, making it strategically important not only for Kenya but also for regional trade. It carries substantial freight between the Port of Mombasa and inland markets, including neighbouring landlocked countries.

Its current two-lane configuration has long been associated with congestion, delays and road-safety challenges, particularly because passenger vehicles and heavy commercial trucks share much of the same corridor.

Turning the highway into a controlled-access toll road would represent a major change in how motorists use the corridor. It would also create a potential revenue stream through toll collections to support private-sector investment.

However, the current procurement notice does not mean construction is about to begin. The feasibility and transaction advisory stages must first establish the project's technical, financial and commercial viability.

The consultant will also help determine the appropriate PPP structure and prepare the project for eventual engagement with potential investors.

The latest move therefore marks another stage in a project that has gone through several proposed financing and delivery models over the years.

For motorists and freight operators, the significance will ultimately depend on whether the process succeeds in turning the existing highway into a higher-capacity, safer and more predictable corridor.

For now, KeNHA is back at the table with a new structure: upgrade the road that already exists, bring in private capital, and recover the investment through a long-term operating arrangement.