An artistic presentation of the Nairobi Expressway

This article on The Nairobi Expressway was contributed by the KENHA communication team for publication in Volume 3(2020/21) of the Engineers’ Year Book. 


A curious young mind in a matatu (about 7 years old) stares at steel structures towering above the ground around Bellevue area of Mombasa road asks the mother, “mum kwani hii barabara itapita wapi?” (Loosely translated, “ Mum, where will this road pass?”). The child’s spatial awareness was ignited by his attempts to try and figure out why there are pillars being constructed in the middle of the road.

Our ability as human beings to comprehend three-dimensional images and shapes, which is a primary function of the right side of the brain is key in solving puzzles, figuring out maps and taking part in any type of construction or engineering project. This trait, known as “spatial intelligence” is one of other cognitive skills that human beings possess in different measures. While some are verbal thinkers, others are visual thinkers who either relate more with schematic images or pictorial images.


Since the late 1990s there have been discussions to expand the section of the Northern Corridor, (A8) between Machakos Turnoff – JKIA – Nairobi CBD and Rironi. The Nairobi Expressway was an inevitable and necessary component of Kenya’s and the larger regional infrastructural network.

The Nairobi Expressway is a key section of the Northern Corridor which provides passage to 85% of cargo destined for the neighbouring landlocked countries. The Northern Corridor is an important transport route connecting the countries of East Africa — from the Port of Mombasa in Kenya to landlocked Uganda, Rwanda, Burundi and the Democratic Republic of the Congo.

At peak hours, it currently takes motorists 2 hours to commute from Mlolongo to Waiyaki way in Nairobi. Nairobi has therefore become a bottle neck for the Northern Corridor. There have been interventions to expand the section between Athi River — Machakos Junction and the Waiyaki Way — Rironi section. The intervention that joins these two projects is the Nairobi Expressway.


The design of the Nairobi Expressway’s elevated section is slowly coming to life at a site close to Nextgen Mall where elevation of the road will start. Steel structures cemented into the foundation of the columns that will hold the elevated section are now visible and it is a fact that out of the total 27 kilometres of the Nairobi Expressway, 11.2 kilometres will be elevated. Elevation of the road has been necessitated by the lack of sufficient space to construct four lanes running parallel to the existing section of the A8 road.

Works along the elevated section are using the fabricated bridge technology. In this technology, the main components of the upper and lower structure of the bridge are prefabricated and assembled on site in a factory or a yard.

This technology is viable for a number of reasons:

  1. It reduces construction period by 50%
  2. Standardization of the structures helps to control the quality of construction
  3. The method significantly reduces risk factors and improves safety
  4. It is environmentally friendly due to lower carbon emissions during construction
  5. It significantly reduces the disruption that is caused along the existing A8 highway.


Fact: The Nairobi Expressway is expected to create 3000 jobs during construction and 500 jobs in its operation phase.

Observing the pattern of construction works on site at the Nairobi expressway reminds one of how the millipede moves. A well segmented body with each segment carrying two pairs of legs. Movement cannot happen except in a flawless wavelike motion propelling the body forward. Unless the energy transmitted from the rear side of the body arrives very systematically to the front side, there is no movement. Truly, even in the world of road construction the whole can only be understood through knowledge of its parts and the parts, as products of the division of the whole, can be understood only through knowledge of the whole.  One key person that exemplifies this statement at any construction site is the foreman.

According to “Youth in Construction”, an initiative by the SA Forum of Civil Engineering Contractors (SAFCEC)” The foreman is a first-line supervisory position. A Foreman has extensive knowledge of the trade and the work involved, along with an ability to resolve problems with appropriate and timely decisions. A Foreman reports directly to a General Foreman or Site Agent. Anyone in and around the world of construction can tell you that a foreman can make or break the chances of success of any project.

A Foreman must have a technical qualification, good written and verbal communication skills, negotiation skills, knowledge of civil engineering construction processes, plant and equipment, production control, safety, material control, read and interpret drawings among other things. Of course, the only way to determine a good foreman like any other job is by looking at the track record. The images captured in this article are a humble tribute to the work done by foremen.


As the sun sets in Nairobi and everything slows down, the lights are turned on for the Nairobi Expressway project. Minimizing traffic disruptions remains a key objective in the execution of the construction works being undertaken along one of the busiest roads in the country.

In the dead of the night, trucks ferrying materials can be seen buzzing in and out of the work sites. Graders run up and down the layers of material under powerful lights that provide the workers with the benefit of vision at night.

At night, as you drive from town past the JKIA turnoff section and up the overpass, a look to your right reveals the Expressway at the centre alignment of the road, beaming with activity. On site, the sound of engines running shift your mind away from the evening chills.

The people on ground are sharp and alive, quick to pick out and deal with anything that looks out of the ordinary. Even as working at night minimises traffic disruption, workers at night are required to be more alert to avoid accidents.

The implementation of construction works along the Nairobi Expressway both in daytime and in night time will be a significant factor in the timely completion of the project. This strategy is and will continue minimising traffic snarl ups that come with road construction works along an extremely busy highway.


A look into the archives unveils a thesis published by the University of Nairobi in 1992 “Industrialization of Athi River town” by CALEB  MC’ MIRERI (today he is Prof. Mireri).

In introducing the paper, the scholar makes two assumptions:

(a) That Athi River town has great potential forindustrial development.

(b) That through proper planning and development co-ordination, full potentials can be tapped with minimal adverse effects.

At the time (1992), the industrial sector contributed to 27% of the GDP, ranking second after agriculture. Twenty-eight years later, the sector contributes 16%, agriculture 34% and services 43.2%.

Although the fast returns on investment yielded by sectors such as the real estate may be so seductive to an economy, history teaches us that we should not disregard the ever-present coconuts for the seasonal mangos (Swahili proverb loosely translated, of course).

Mireri’s faith in Athi River town was not far-fetched because the rate of industrial growth in Athi River town was at 10% which was much higher than the projected national growth rate of 6.4%. The employment growth rate at the same period of time in the town was 10.6% which was more than twice the projected 4.4%.

Some of the factors that suffocated the growth potential of the town were lack of an uptown-date plan to guide the growth of the town and a lag in the infrastructural provision needed by the town. According to Mireri, to harness the full industrial development potential of Athi River town will require proper planning and co-ordination of development activities.

Today Athi River and other satellite towns of Nairobi like Syokimau, Mlolongo and Kitengela are in the middle of what could be one of the greatest infrastructural interventions for Nairobi and its environs. The Nairobi Expressway is set to significantly reduce travel time through the city of Nairobi.

An industry processing raw materials in Athi River in the next two years shall be able to transport products through the city of Nairobi to Limuru and its environs with minimum time wastage. The dualling of the road section between Machakos turnoff and Mlolongo, will also significantly impact the areas beyond Athi River town which are set to benefit from the growth opportunities that will come with the project.

To embrace the Nairobi Expressway is more than just looking at how it will benefit Nairobi as a town. It is to also look outwards and see what opportunities it will create for the fast-growing outskirts of Nairobi. The road creates the opportunity for growth, and the people will determine what growth trajectory will be. The benefits of nurturing the industrial sector for a country like Kenya are priceless.

For anyone who may have a little spatial thinker running around the house, don’t wait for school to identify and cultivate that strength. Perhaps take a day out along the Nairobi Expressway and let him meet an engineer who can confuse him more.



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