Understanding Why People Speed and Creating Strategies
In November 2023, I attended a roundtable on speed management, co-hosted by the Chartered Institution of Highways & Transportation (CIHT) and the Parliamentary Advisory Council for Transport Safety.
I finally got round to sharing some thoughts on how government, highways authorities, and practitioners can get better at understanding why people speed and creating strategies and interventions that change this.
To achieve desired reductions in KSIs (Killed or Seriously Injured incidents), public compliance with speed limits is crucial, regardless of how these limits are set.
There is real opportunity for the Highways, Transportation and Road Safety sector to bring driver behaviour closer in line with speed limits. However, to achieve this, a better understanding of the reasons why people speed, supported by interventions, tailored to overcome identified barriers, is needed.
To date, the main levers used to promote safe and responsible driving include:
Training: to provide the necessary competences.
Education: to provide knowledge of what is required and the reasons for this.
Persuasion: to drive intention.
Skills based training is fundamental, equipping individuals with necessary competences, such as the ability to and drive safely at different speeds and in different conditions.
Education assumes that with the provision of the right information, humans will adopt an optimal choice or behaviour. For example, “I know the speed limit of this road, the reasons why, and the consequences of breaking the legal limit. Therefore, I will drive within the speed limit as it is in my best interest to do so”. This is based on Subjective Expected Utility Theory which is founded on the premise that humans always act rationally. However, people do not always think and act rationally, and as a result, information-based models are limited in their effectiveness. Importantly, awareness only explains around 4–5% of our behaviour (Heiskanen & Laakso 2019).
Persuasion assumes that aligning attitudes and beliefs with a specific behavioural goal will modify behaviour. For example, “I believe that speeding is dangerous and irresponsible. I consider myself to be a decent person with a sense of societal responsibility, therefore, I will drive within the legal limit and reduce my speed accordingly”. Unfortunately, not only is altering fundamental beliefs very challenging, but attitudes and beliefs only account for between 13–18% of human behaviour (Heiskanen & Laakso 2019).
If we accept that possessing the right knowledge and attitudes accounts for only 17–23% of our behaviour, then we must also accept that a failure to address the wider determinants of speeding will result in the sector falling short in its aspiration for zero deaths on UK roads a vision adopted by many local authorities and their partners. To achieve a meaningful shift in behaviour, required to support safe systems approaches, highways authorities must look beyond the obvious and respond in a more nuanced, layered way.
There are many reasons for persistent speeding, some more obvious than others. Factors often overlooked include personality traits (type A personalities have an association with speeding behaviour) the enduring power of habit, scarcities of time, attention, and self-restraint. Other factors include the human reliance on ‘heuristics’ (rules of thumb) that can lead to cognitive bias’s resulting in poor judgement and error. For example, people tend to underestimate risk on familiar routes – conversely, people are far less complacent in areas of low familiarity even when relative levels of risk in the familiar and unfamiliar area are roughly the same.
Context also influences behaviour. This includes the social context, where we see a tendency to mimic majority behaviour and environmental factors which can 'cue' individuals to behave in certain ways. For example, a straight road with an unencumbered view can act as a cue to drive at speeds far surpassing the 'safe speed' for that road.
Why then is it acceptable to commission speed awareness campaigns based solely on assessment of superficial design quality, without requiring explanation of the insights underpinning the proposed approach, and the data that informs them? How were the resulting assets tested prior to roll out, and was every opportunity to change behaviour fully considered prior to settling on a favoured approach?
Nor should it be valid to simply provide more information and education, without first assessing existing levels of understanding. Simply saying it ‘again, but louder’ is a futile pursuit.
The sector must treat behaviour change with the same professionalism, seriousness, and rigour it gives to developing innovations in engineering or technology.
On a positive note, our understanding of human behaviour has significantly advanced over the past decade. There are frameworks, models, and approaches from emerging fields, such as applied behavioural science, that offer a better lens through which to interpret behaviours such as persistent speeding and will align them with informed evidence-based strategies that hold the potential to verifiably change behaviour.
However, none of this will happen without a paradigm shift in thinking, coupled with political will and the resource to support it.
A quote often misattributed to Einstein is that "The definition of insanity is doing the same thing over and over again and expecting a different result". Whether Einstein was the source of this quote or not, the sentiment is valid and still holds true today.
It’s time for a step change and it’s long overdue.