Welcome to Day 2 of our #30DayMapChallenge series! Yesterday we explored points (health facilities). Today, we trace the lines that connect—or fail to connect—Nigeria’s communities.
Today’s theme: Lines
AT A GLANCE:
- Road network visualization revealing Nigeria’s transportation infrastructure across all 36 states + FCT
- Connectivity analysis: Which communities are linked by paved roads, and which remain isolated
- Infrastructure gaps: Rural areas often rely on unpaved or seasonal roads
- Interactive exploration: Zoom into any region to see road density and quality
Reading time: 5 minutes | Map Challenge Day: 2 of 30 | Theme: Lines
The Map: Roads That Connect, Roads That Don’t
Lines on a map are more than geometry—they’re lifelines. A paved road means a child can reach school during rainy season. A highway means farmers can get crops to market before they spoil. The absence of a line means isolation, lost economic opportunity, and limited access to healthcare.
GRID3 NGA - Settlement and Infrastructure Data
Note: This visualization shows the spatial distribution of Nigeria’s road network. Road classification and condition data reflect available open data sources and may not capture recent infrastructure developments.
How to Explore This Map
- Toggle road layers using checkboxes in the top-left to show/hide different road types (reduces clutter)
- Zoom in to see the density of road networks in different regions
- Click any road to see details like road name, type, and surface quality
- Compare urban vs rural areas: Notice how road density varies dramatically
- Trace major highways: Only show motorways/trunk roads to see the primary network
Tip: Start with just motorways and primary roads visible, then toggle on local roads to see the full density.
About the Data
Dataset: Our visualization contains 6,274,965 road features from GRID3 Nigeria’s open infrastructure data, covering all 36 states + FCT.
Road Network Hierarchy:
Federal trunk roads (A-roads): Major highways connecting state capitals and economic centers
State roads: Connecting LGA headquarters and major towns
Local roads: Rural access roads, often unpaved or seasonal
Urban-Rural Divide: Lagos, Abuja, Kano, and Port Harcourt show dense road networks. Rural states in the Northeast and Northwest show significant connectivity gaps, with many communities accessible only by unpaved roads that become impassable during rainy season.
Economic Impact: Research shows that proximity to paved roads correlates strongly with market access, school enrollment, and healthcare utilization.1
Why Lines? Why Roads?
Lines are the connective tissue of spatial analysis. After mapping points (facilities, settlements), we ask: How do people move between them?
For Nigeria’s 220+ million people, roads are the primary mode of connection:
Where are the highways? Major trunk roads like the Lagos-Ibadan Expressway, Abuja-Kaduna road, and East-West road carry millions of passengers and billions in trade annually.
Where are the gaps? Zoom into rural Borno, Yobe, or Zamfara. The sparse line work reveals communities that remain isolated, particularly during the rainy season when unpaved roads become impassable.
What’s the quality? Not all lines are equal. A paved, maintained federal highway enables year-round connectivity. An unpaved rural road might only be passable 6 months a year.
What the Data Reveals
Our dataset contains 6,274,965 road features—from major highways to rural tracks. This granular view reveals stark patterns:
Network density tells a development story: Lagos and Abuja show dense, interconnected road grids. Zoom into rural Borno or Zamfara and you’ll see communities 50+ km from the nearest all-season road.
Accessibility gaps are severe: Urban centers like Lagos enjoy relatively short travel times to essential services. In contrast, rural areas in the Northeast and Northwest show significantly sparser road networks, with many communities far from paved roads—distances that become even more challenging during rainy season when unpaved roads become impassable.
Surface quality matters enormously: Our data includes road surface classification. Paved roads enable year-round connectivity. Unpaved roads—which dominate rural areas—become dangerous or impassable during rainy season, significantly increasing travel times and vehicle operating costs.
Single points of failure: Many rural communities have only one road connection. When that link fails (flooding, insecurity, collapse), entire areas become isolated. The Niger Bridge is a classic example: when congested or closed, regional trade stalls.
The Connectivity Challenge
Nigeria’s road network faces several critical challenges:
1. Maintenance Crisis
Many federal and state roads suffer from years of deferred maintenance. Potholes, erosion, and structural failures make even major highways dangerous and unreliable.
2. Rural Access Gaps
While urban areas enjoy relatively dense road networks, rural communities—where agriculture remains the economic backbone—often lack all-season road access. This limits:
- Market access for agricultural products
- Healthcare access during emergencies
- Educational opportunities when roads become impassable
3. Regional Disparities
The Southern states generally have denser road networks compared to Northern states. This reflects both historical development patterns and geographic challenges (terrain, climate, population distribution).
4. Security Implications
Poor road infrastructure and limited alternative routes create vulnerability. When major highways become insecure or impassable, entire regions can be cut off from economic activity and essential services.
How We Use This Data
Road network data isn’t just for pretty maps—it’s a planning tool:
Network analysis helps us calculate travel times from any community to essential services. Overlay this with Day 1’s health facility locations and you can identify underserved populations.
Investment prioritization: Given a budget to pave N kilometers of road, which segments would connect the most isolated communities? Spatial optimization can answer that.
Climate resilience: By overlaying flood hazard maps with road networks, we identify which communities become completely isolated during rainy season—and where alternative routes are critical.
Multi-layered insights: Combining road networks with agricultural zones, population density, and market locations reveals where infrastructure investment would unlock the most economic opportunity.
Lines That Matter
Every line on this map represents possibility:
- A farmer getting cassava to market
- An ambulance reaching a patient
- A child attending school consistently
- Economic opportunity flowing between communities
But the absence of lines matters just as much. The gaps reveal where Nigeria’s connectivity promise remains unfulfilled.
About the #30DayMapChallenge
The #30DayMapChallenge is a daily mapping and cartography challenge throughout November. Created by Topi Tjukanov, it brings together the global geospatial community to explore creative ways of visualizing spatial data.
This is Day 2: Lines—the connections that bind (or fail to bind) places together.
Over the next 28 days, we’ll continue exploring Nigeria’s spatial story through different cartographic lenses.
Tomorrow: Day 3 — Polygons: Nigeria’s Administrative Boundaries and Governance
We’ll explore how Nigeria is divided, governed, and how these invisible boundaries shape service delivery.
Share This Map
Help us spread the word about Nigeria’s road infrastructure challenges!
Suggested post:
“Every line on this map is a lifeline. Mapping Nigeria’s road network reveals which communities are connected—and which remain isolated. #30DayMapChallenge #Nigeria #Infrastructure #SpatialAnalysis”
References
Want to explore Nigeria’s spatial data? Contact us
Follow our #30DayMapChallenge series: Nexus Insights
Footnotes
-
Ouma, P. O., et al. (2018). “Access to emergency hospital care provided by the public sector in sub-Saharan Africa in 2015: a geocoded inventory and spatial analysis.” The Lancet Global Health, 6(3), e342-e350.
Documents correlation between road access and healthcare utilization in sub-Saharan Africa. ↩