When we talk about transport system performance, the conversation tends to gravitate toward the
physical: road geometry, signal timing, pavement condition, fleet age and network capacity. These matter, of
course. But they are only half the story. The other half, often underestimated, is human factors: the perceptual,
cognitive and behavioural characteristics of the people who design, operate, regulate and use transport systems.
Engineers can design roads to the highest standard, but if drivers misjudge speed, pedestrians cross at
undesignated points, or operators are fatigued or distracted, the system underperforms regardless of how sound
the engineering is. The WHO estimates that road crashes kill around 1.19 million people every year worldwide,
and human error is consistently identified as a contributing factor in most of these crashes. Performance is not
simply a function of infrastructure quality; it is a function of how well that infrastructure accommodates human
capabilities and limitations.
A Problem Shaped by Context
The human factors challenge differs sharply by context. In high-income countries, it tends to focus on
smartphone distraction, speeding on well-engineered corridors, and complacency born of over-trust in driver-
assistance systems. Strong enforcement, standardised training and forgiving infrastructure design all help
absorb the consequences before they turn fatal.
In Sub-Saharan Africa, the picture is more complex. Traffic is mixed among pedestrians, cyclists,
motorcyclists and informal transport operators, with little physical separation, demanding constant, high-stakes
judgement from all road users. Licensing is inconsistently enforced, so hazard-perception competency varies
widely, and infrastructure often does not forgive mistakes: many roads lack shoulders, signage, lighting or
pedestrian facilities, so an error that might be inconsequential elsewhere becomes fatal here. Fatigue, economic
pressure on commercial drivers, and limited enforcement capacity compound the problem. Human error is both
more likely to occur and less likely to be absorbed safely.
The scale of this imbalance is stark. According to Africa Status Report on Road Safety 2025, the region
accounts for 24% of the world’s road traffic deaths despite holding only 15% of the global population and just
4% of the global vehicle fleet. At 19.6 deaths per 100,000 people, the African region accounts for the highest
fatality rate of any region. Further, according to WHO’s Road Safety in the WHO African Region 2023 report
Between 2010 and 2021, fatalities in the region rose by 17%, even as the global figure fell by 5%. This is not a
story of more vehicles causing more harm; it is a story of a system with less capacity to absorb the human error
all road systems generate.
From Driver Behaviour to Systems Design
Human factors challenges are not simply a driver’s behaviour problem to be solved with awareness
campaigns alone; they are a systems design problem, and traffic engineers are well placed to lead the response.
This is the logic behind the internationally recognised Safe System approach, endorsed by the WHO, which
assumes people will inevitably make mistakes and asks infrastructure to protect them when they do. In practice,
this means designing for the human, not the ideal user:
● Forgiving design: traffic calming, separation of vulnerable users, better lighting and signage.
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● Standards fit for the real traffic mix of motorcycles, informal transit and pedestrians.
● Low-cost, high-impact fixes: speed bumps, rumble strips, raised crossings.
● Stronger licensing and hazard-perception training, developed with transport authorities.
● Data-led prioritization of crash-prone locations; and
● Enforcement is treated as core infrastructure, not an afterthought.
Transport performance is ultimately a story about people: how they perceive, decide and act within the
systems we build for them. In Sub-Saharan Africa, where infrastructure and enforcement gaps compound
human error rather than absorb it, there is a genuine opportunity for traffic engineers to lead with human-centred
design. The most successful transport systems will not expect perfect human behaviour; they will be designed
to work well even when humans are, simply, human.
Eunice Githu
Assistant Engineer, Glince Limited
Visit us: https:/https:/glinceltd.com/
Contact us: info@glinceltd.com
