Building 75 km of six-lane dual carriageway takes large-scale earthworks and a carefully layered pavement. The Schedule of Activities for ICCO's Nasarawa urban roads project shows how much work went into the road before the final asphalt was laid, from surveys and soil tests to more than a million cubic metres of embankment fill.
This article follows the road from the ground up: the design studies that shaped it, the earthworks that formed its platform, and the six pavement layers that now carry Nasarawa's traffic.
Key facts
- Road length: 75 km of six-lane dual carriageway
- Right-of-way cleared: 3,375,000 m²
- Excavation: 525,000 m³ common + 15,000 m³ in rock
- Embankment fill: 1,125,000 m³
- Asphalt: 50 mm binder course + 50 mm wearing course
- Certified complete: 27 June 2026
Design first: the studies behind the road
The project began with a complete design for the 75 km dual carriageway. ICCO carried out:
- Topographic surveys, which map the shape and levels of the ground along the route;
- Geotechnical investigations, which test the soils the road will sit on;
- Traffic and axle-load studies, which measure how many vehicles use the route and how heavy they are;
- Hydrological and hydraulic studies, which estimate how rainwater flows towards the road; and
- detailed geometric, pavement, drainage, bridge, road-safety and lighting designs.
Traffic and axle-load studies matter because they show how many vehicles, and how heavy, the road must carry over its life. These figures set the thickness of each pavement layer. A road designed for light cars alone would fail quickly under loaded trucks, so getting the loading right at the start protects the whole investment.
Preparing the ground
On site, crews cleared and grubbed 3,375,000 m² of right-of-way, an area equivalent to a strip about 45 m wide along the full 75 km. Clearing and grubbing removes vegetation, stumps and roots so that the road is built on firm material rather than organic soil that would compress over time.
The crews then carried out 525,000 m³ of common excavation in cut and 15,000 m³ of excavation in rock. Total embankment fill, drawn from cut and borrow areas, reached 1,125,000 m³.
| Earthworks activity | Executed quantity |
|---|---|
| Clearing and grubbing of right-of-way | 3,375,000 m² |
| Common excavation in cut | 525,000 m³ |
| Excavation in rock | 15,000 m³ |
| Embankment fill from cut and borrow areas | 1,125,000 m³ |
Reusing excavated material as fill reduces the need to bring in material from elsewhere, which saves haulage and limits disturbance to surrounding land. The embankments give the road a stable, raised platform above the surrounding ground.
Building the pavement, layer by layer
The pavement was built in layers, each spreading the load before it reaches the soil below. A truck tyre presses on a small patch of asphalt; by the time that force has passed down through the base, subbase and capping, it is spread over a much wider area, so the natural ground underneath carries only a fraction of the original pressure.
| Layer (bottom to top) | Executed quantity | What it does |
|---|---|---|
| Improved subgrade / capping | 363,375 m³ | Strengthens the formation and gives a uniform working platform |
| Granular subbase | 454,500 m³ | Spreads loads and supports the base course |
| Graded crushed stone base course | 436,500 m³ | Main load-carrying layer beneath the asphalt |
| Prime coat | 2,182,500 m² | Seals the base and helps the asphalt bond to it |
| Asphalt binder course, 50 mm | 1,642,500 m² | Adds strength to the bound layers |
| Asphalt wearing course, 50 mm | 2,092,500 m² | Gives drivers a smooth, durable riding surface |
The prime coat seals the crushed stone base and helps the asphalt bond to it. The binder course adds strength, while the wearing course gives drivers a smooth, durable riding surface. Because the wearing course is the layer tyres actually touch, it is the one road users notice: its evenness decides how comfortable and quiet the journey feels.
Why the layers matter
Each layer is chosen for a job. Granular layers carry and spread load and let water drain away; the asphalt layers resist wear and keep water from soaking down into the base. When any layer is thinner or weaker than it should be, the road above it starts to rut and crack. That is why the pavement design depends on the traffic and soil data gathered at the start of the project.
Certified complete
All 75 km of road construction and dualisation works were completed and certified on 27 June 2026, as recorded in the Certificate of Completion issued by the Nasarawa State Urban Development Board.
More on the Nasarawa 75 km urban roads
This article is part of a five-part series on the project:
- ICCO Completes Nasarawa's 75 km Six-Lane Urban Road Project – the scope, value, timeline and completion of the project.
- Five 30 m Bridges Delivered on Nasarawa's 75 km Urban Road – the piles, beams, bearings and load testing of the five bridges.
- How Drainage and Erosion Control Protect Nasarawa's New Roads – the drains, culverts and erosion control that keep water off the road.
- 1,878 LED Lights and More: Road Safety on Nasarawa's 75 km Road – street lighting, road markings, guardrails and pedestrian facilities.
Frequently asked questions
How much earth was moved on the Nasarawa 75 km road?
Crews carried out 525,000 m³ of common excavation and 15,000 m³ of rock excavation, and placed 1,125,000 m³ of embankment fill drawn from cut and borrow areas.
What are the pavement layers of the Nasarawa road?
From the bottom up: improved subgrade or capping, granular subbase, graded crushed stone base course, prime coat, a 50 mm asphalt binder course and a 50 mm asphalt wearing course.
What does a prime coat do?
The prime coat seals the crushed stone base and helps the asphalt layers bond to it.
Why were traffic and axle-load studies needed?
They show how many vehicles, and how heavy, the road must carry over its life. These figures set the thickness of each pavement layer.
Comments
Post a Comment