Kenya National Highways Authority data has placed Mombasa’s Dongo Kundu Bypass at the top of the country’s road cost rankings, with the Mwache-Mteza section coming in at about Sh2.7 billion per kilometre.
The nine-kilometre Phase Two stretch is budgeted at Sh24 billion, making it the most expensive road project in Kenya’s history. KeNHA says the price is driven largely by the two sea bridges on the route, which together cover 2.1 kilometres.
The disclosure comes as debate grows over the cost of public infrastructure and the strain it places on the Treasury, which has allocated Sh116 billion for road construction this year.
KeNHA says Mombasa roads are generally more expensive than similar projects elsewhere because of terrain and the need for heavier engineering work. The authority also points to bridges, box culverts, urban congestion and other design demands as major cost drivers.
The bypass is part of the Mombasa Port Area Road Development Project, which is intended to ease congestion around the port. The 27-kilometre dual carriageway is being built in phases.
Phase One, the 11-kilometre Miritini-Mwache section, was officially opened in June and is priced at Sh1.15 billion per kilometre. KeNHA links that figure to difficult terrain and security features, including a canopy over a one-kilometre stretch along the Moi Airport boundary.
Phase Three, the seven-kilometre Mteza-Kibundani section, connects the bypass to the Likoni-Lunga Lunga Road and costs Sh571.4 million per kilometre. That section includes a sightseeing bay and 88 hectares of replanted mangroves.
Other Mombasa projects also rank among the country’s costliest. The 2.6-kilometre Magongo-Changamwe dualling is priced at Sh930.9 million per kilometre, while the 11.3-kilometre Mombasa-Kwa Jomvu section of the Mombasa-Miritini highway upgrade stands at Sh532 million per kilometre.
In Nairobi, the proposed Western Bypass is the most expensive road per kilometre at Sh965.9 million. The 17.6-kilometre Ruaka-Gitaru road is expected to cost Sh17 billion and will include four lanes, service roads on both sides and interchanges at Wangige, Kihara, Ndenderu and Ruaka.
The Western Bypass was first disclosed two years ago and drew criticism because its cost was compared with the 12-lane Thika Road, which was built seven years ago at Sh600 million per kilometre.
Also in Nairobi, the 26-kilometre James Gichuru Junction-Rironi Road is costing Sh629.5 million per kilometre. The 28.5-kilometre Southern Bypass stands at Sh659.3 million per kilometre, with KeNHA citing 25 kilometres of service roads, five major flyovers and street lighting.
Land acquisition and the relocation of utilities such as electricity lines, water and oil pipelines, fibre optic cables and sewers have also pushed up costs in the capital, according to the authority.
KeNHA says roads with interchanges and flyovers are more expensive to build. In Nakuru County, three interchanges have been constructed at Sh580.8 million per kilometre across a five-kilometre stretch.
By contrast, rural roads are far cheaper, averaging between Sh10 million and Sh150 million per kilometre because land is easier to acquire, materials are more available and utility relocation costs are lower.
