Even the best drivers make mistakes. But are all mistakes created equal? The Safe System acknowledges the human reality that we’re all flawed, but we can unpack aberrations on the road into the categories: errors and violations.

Back in the 90s, Reason and colleagues were on the forefront of this categorising and created three buckets: violations, dangerous errors, and harmless lapses. Violations, they argued, stemmed from social and motivational factors – think rushing to meet a deadline or succumbing to peer pressure. Errors, on the other hand, were cognitive mistakes – a missed stop sign, a misjudged turn. And then there were the harmless lapses, momentary blinks in the driving task.

Fast forward to a Western Australian study by Blockey and Hartley which found similar but had some other lenses. They discovered an age dynamic: young drivers, it seems, are prone to both dangerous errors and violations, while seasoned drivers stick mainly to violations. Gender also played a role, with women reporting more dangerous errors and men more dangerous violations. Interestingly, drivers with extensive experience and those with speeding convictions leaned more towards the latter category.

This video is a vivid reminder of these violation categories. We see drivers using the pedestrian crossing facilities at this intersection, a clear display of intentional disregard for the rules.

Understanding the psychology behind errors and violations is crucial for designing effective safety interventions.


Blockey & Hartley, Aberrant driving behaviour: errors and violations, Ergonomics, 2007

Reason et al., Errors and violations on the roads: a real distinction?, Ergonomics 1990