Impact case study database

Legal changes based on Dr Walker’s research are saving around 7 lives each year in Australia, preventing around 260 more serious injuries, and saving the Australian economy more than AUD34,000,000 annually due to lives saved.

Dr Walker’s research demonstrated empirically that the variance in safety during overtaking manoeuvres attributable to the rider’s appearance or actions was far lower than the variance in safety associated with non-cyclist variables such as inter-driver differences and situational factors. In other words, Walker’s work demonstrated for the first time that how a bicyclist looks or acts could only ever be a minor factor in determining their safety, and the behaviour of the overtaking driver, and their interaction with the physical environment, is far more important. As such, the research demonstrated that, above all, it is driver behaviour that needs to change to achieve greater safety. This insight directly informed policy changes, and also fed into public understanding of this road safety topic.

How the Impact occurred: The Amy Gillett Foundation

Walker’s research has proved particularly important in Australia, which has taken the lead in legislating for bicyclist safety during overtakes. Australia had identified collisions during overtaking as a critical problem: at the time this research began in 2006, central government in Australia was reporting “the most common type of crash in which cyclists were fatally injured was the cyclist being hit from behind by a motor vehicle travelling in the same lane in the same direction” [E, p.2]. In 2008, Dr Walker’s research was taken up by the Amy Gillett Foundation, a leading cycling safety organisation in Australia, driven by a core mission to reduce the death and injury of cyclists. The Amy Gillett Foundation describe Dr Walker’s findings as “pivotal” [A, B], explicitly listing it as the starting point for their A Metre Matters campaign to address overtaking collisions for bicyclists [A, B]. “Dr Walker’s finding about the variation in lateral clearance distance was the specific feature of the paper that provided insights to the campaign”, they write in their evidence letter [B]. A member of the Foundation used the methods and findings from Walker’s study as the basis for additional research in the Australian context that was published in 2011, and the combined scientific data [A,B] allowed the Foundation to argue to government that it was specifically driver behaviour during overtakes that needed regulation if bicyclist safety was to be improved. In 2009 The Foundation’s A Metre Matters campaign was launched by the CEO of the Amy Gillett Foundation, with the Australian Minister for Infrastructure and Transport, Anthony Albanese. Between 2010 and 2012 an education campaign was rolled out across Australia including billboards and advertisements. However, the campaign aimed to go beyond education, to instigate legal changes.

Influencing legal changes in Australia

As detailed on the Foundation’s website [A], between 2014 and 2020 all of Australia’s 8 states and territories trialled, and then adopted, laws specifying minimum passing clearances when overtaking a bicyclist, and in each case this was directly in response to the charity’s lobbying [A]. The Amy Gillett Foundation lists that one of its missions is to continue to “promote actions to make cycling safer in Australia, including the A metre matters laws across Australia, to make sure drivers pass cyclists safely” [G]. The population of Australia potentially affected by this law can be estimated from the overall population of 25,000,000. Based on data from 2019, for cyclists aged 50 or over (the population with the lowest figures, thereby providing the most conservative estimate), at least 6% of Australians cycle on a weekly basis, 10% monthly and 17% yearly. This equates to at least 1,500,000 people who cycle weekly, 2,500,000 monthly and 4,250,000 yearly. On average 31.7% of cycling was for transport purposes, suggesting at least this proportion of cyclists are road-users. Using these extremely conservative figures, this would indicate that across the whole population, for the lifetime of legal changes that can be traced back to Dr Walker’s research, the changes protect approximately 475,000 people weekly, 792,500 monthly and 1,347,250 yearly [H, p.9, 11]. In particular, considering the number of commuters, figures from 2016 indicate that there were a combined total of 75,807 commuters in Melbourne, Sydney, Brisbane, Perth, Adelaide, Darwin and Hobart, which suggests that there are at least this many commuters across Australia protected by the new laws [I].

Saving lives, reducing injury rate and benefitting the economy through the A Metre Matters law

In each state or territory, the new overtaking laws were first introduced from 2014 onwards on a trial basis and later made permanent once official trials demonstrated they were effective at changing behaviour, and thereby improving road safety (for example see [C] for the New South Wales evaluation of their passing law trial). As the states would not introduce permanent legal changes until convinced they would work to improve safety, these government trials provide powerful evidence for the efficacy and impact of these laws that were underpinned by Dr Walker’s research. The government evaluation from New South Wales estimated, after analysing 5,979 behavioural observations, as well as police records, that minimum passing distances led to a 15% reduction in casualty crashes [C, p.7]. In the years preceding the laws, there was an average of 48 cyclist deaths per year in Australia [E, p.5]. The New South Wales data thereby allow us defensibly to estimate the laws derived from Dr Walker’s research are saving around 7 lives each year across the country. We can also estimate that these laws are preventing approximately 260 more serious injuries [D – Note that Australia’s public data only report deaths, not injuries, so this value is estimated using the UK death:serious-injury ratio for cyclists, which should be comparable]. Australia’s statistical value of life is AUD4,900,000 [F], meaning that even in the crudest monetary terms, and only counting the deaths, the safety improvements arising from this law are worth more than AUD34,000,000 to the Australian economy each year.