Ruto launches Sh170 billion Rironi-Mau Summit highway dualling
National
By
Ronald Kipruto
| Nov 28, 2025
President William Ruto during the launch of the dualling of the 175-kilometer Rironi-Mau Summit project. [PCS]
President William Ruto has officially launched the dualling of the 175-kilometer Rironi-Mau Summit highway, a transformative infrastructure project expected to ease congestion and boost trade along one of Kenya's busiest corridors.
The project is estimated to cost between Sh170 billion and Sh200 billion and will be completed by June 2027, Ruto said during the launch in Kamandura, Kiambu County on Friday, November 28.
The highway upgrade will feature a four-lane dual carriageway from Rironi to Naivasha and a six-lane dual carriageway between Naivasha and Nakuru, replacing the initial two-lane proposal the president rejected as inadequate for future traffic demands.
The highway currently carries an estimated 20,000 vehicles daily, a figure projected to grow by 4 percent annually.
"This project we launch today is more than a highway; it's a gateway to prosperity, unity and transformation. It positions Kenya as a leader in innovative financing, in modern transport, in public-private partnership," Ruto said.
China Road and Bridge Corporation (CRBC) and the National Social Security Fund (NSSF) consortium won the contract to implement the project through a public-private partnership.
The president noted the project will create more than 15,000 jobs during the construction period, with young Kenyans gaining skills while helping build the highway.
"This project will create thousands of jobs, with 15,000 young Kenyans gaining skills as they help build this highway. It will not only construct roads, but careers and futures, with local content leading and Kenyan businesses at the centre," he added.
The project is expected to transform a heavily used transport artery that for decades has suffered from chronic congestion, frequent accidents and delays, especially during weekends and holidays.
When complete, the Nairobi-Nakuru-Mau Summit corridor will handle heavy commercial traffic, supported by new interchanges, truck laybys, pedestrian bridges, lighting, barriers, drainage systems and intelligent transport technology to enhance safety.
The project will also upgrade the Nairobi-Maai Mahiu-Naivasha section to handle steep gradients and high cargo volumes, linking to the Naivasha Inland Container Depot.
"Together, these upgrades will modernize the corridor, unlocking faster, safer and more efficient movement of people and goods, not only across Kenya, but across East and Central Africa," the president said.
Ruto noted the route is a vital artery linking Kenya to other East and Central African nations, sustaining the economy and powering regional trade and opportunity.
The state has split the project into two contracts, with the A8 section stretching 174.9 kilometres from Rironi Interchange to the Mau Summit turn-off through Nakuru City, while the A8 South section runs 58 kilometres from Rironi to Naivasha via Maai Mahiu.
Users will be required to pay toll fees determined through an approved tariff framework, with rates regulated to ensure affordability, transparency and sustainability. However, alternative roads will be identified from Rironi to Mau Summit for use by the public who may not want to pay and use the road, said Luka Kimeli, acting director general for Kenya National Highways Authority (KeNHA).
The president revealed the government will break ground on major dual-carriageway corridors in the coming months, including Muthaiga to Kiambu and Ndumberi, Machakos Junction to Mariakani, Mau Summit to Kericho and Kisumu, and Kisumu onward to Busia.
Additional roads include Athi River-Namanga, Karatina-Nanyuki-Isiolo corridor, Makutano-Embu-Meru-Maua, Mtwapa-Malindi, Mombasa-Lunga Lunga, Kericho-Kisii-Migori-Isebania, Nakuru-Nyahururu-Nanyuki, Kisii-Oyugis-Ahero, as well as Nairobi's Northern Bypass, Bomas-Karen-Ngong and Bomas-Ongata Rongai-Kiserian-Ngong.
KeNHA issued a traffic advisory on Thursday warning motorists of major traffic disruptions along the Rironi-Nakuru-Mau Summit highway throughout Friday, affecting both long-distance and local travel between Nairobi, Nakuru and surrounding regions.