How Systems Thinking Could Redefine Transport Safety
TRL’s new guide, Systems Thinking in Transport Safety: Cross Modal Safety Change Programme, published for the UK Department for Transport (DfT), introduces a bold way of tackling safety challenges across road, rail, air, and maritime transport. It challenges long-held habits of siloed thinking, replacing them with a more interconnected, human-centred perspective.
The central premise is straightforward but profound: transport safety can only be improved by looking at the bigger picture. That means examining not just machines and infrastructure, but also the humans operating within these systems, and the social, cultural, and environmental influences shaping their decisions.
Lead author Ianto Guy summarises it neatly: “Our aim must be for no one to be injured or killed when travelling by any mode. Systems thinking is not just about tools, it’s about adopting a mindset that sees the bigger picture, understands interconnections, and anticipates the unintended consequences of decisions.”
Learning from History’s Harshest Lessons
The report draws on infamous incidents to illustrate how reductionist approaches, focusing narrowly on one component, can miss the real root causes of disasters.
- The Herald of Free Enterprise sinking revealed how complacency and poor organisational design can be as dangerous as mechanical flaws.
- The Selby rail crash demonstrated how rare interactions between separate systems, road and rail, can trigger catastrophic consequences.
- Air France flight 447 underscored the dangers of automation when human operators are inadequately integrated into the system design.
In each case, technical systems were functioning as intended, yet the interplay of human error, organisational culture, and unanticipated interactions led to tragedy.
The Principles of Systems Thinking
At its core, systems thinking recognises that:
- A system’s behaviour is more than the sum of its parts.
- Boundaries are rarely fixed and impermeable, external influences can breach them.
- Feedback loops, both positive and negative, must be understood and optimised.
- Delayed effects are common; interventions may take time to show results.
- Human fallibility is inevitable, so systems must be designed to tolerate errors.
The Stoke Pewsey pedestrian safety case study in the guide vividly illustrates how historic infrastructure layouts, urban growth, and modern transport demands intersect in complex ways.
Tools for Practitioners
Part two of TRL’s guide catalogues 22 different methodologies and visual tools, from Soft Systems Methodology to Causal Loop Diagrams. These tools help:
- Visualise complex relationships.
- Map interdependencies.
- Identify vulnerabilities.
- Explore alternative system boundaries.
Crucially, the guide stresses that tools are only aids, true systems thinking is about mindset, not checklists.
Automation and Micromobility
Automation offers huge potential to reduce human error, yet also introduces high-stakes risks if systems fail. TRL argues for robust regulation and careful human-machine interface design to ensure safety without over-reliance on technology.
Micromobility, from e-scooters to cargo bikes, is another growing challenge. It crosses boundaries between transport modes, urban design, and even building safety (due to battery charging risks). Systems thinking can help policymakers navigate these overlapping domains.
Moving Towards Safer Journeys
By engaging all stakeholders and integrating cultural, technical, economic, and environmental perspectives, systems thinking offers a path to transport systems that are not just safer, but more resilient and adaptive.
As the TRL guide makes clear, building safety into transport isn’t about perfection, it’s about designing systems that can absorb shocks, learn from failures, and evolve with changing circumstances.
