Road safety should not be based on half facts

A cycling crossing of Luas tracks: Can you see the tram traveling at speed?

“Supporters of helmets often tell vivid stories about someone they knew, or heard of, who was apparently saved from severe head injury by a helmet. Risks and benefits may be exaggerated or discounted depending on the emotional response to the idea of a helmet. For others, this is an explicitly political matter, where an emphasis on helmets reflects a seductively individualistic approach to risk management (or even ‘victim blaming’) while the real gains lie elsewhere.”

That’s Ben Goldacre, of Bad Science fame, and David Spiegelhalter, Winton professor for the public understanding of risk, writing in the British Medical Journal about the complex issue of mandatory bicycle helmets.

The article was prompted by research into the effect of Canadian helmet legislation which concludes that on hospital admission for cycling head injuries “seems to have been minimal” (free to access also on the British Medical Journal). It’s based on data from 1994 to 2008, and Goldacre and Spiegelhalter point out how the study has “somewhat superior methodology” compared to the research which has been favourable to cycling helmets.

Yesterday the Road Safety Authority issued a press release stating that the National Neurosurgery Centre at Beaumont Hospital had the following number of head trauma transfers, broken down by road user group: Cyclists 13, motor vehicle users 10, pedestrians 7, and motorcyclists 5.

Can you see the tram yet?

The press release quotes David O’Brien, consultant neurosurgeon and clinical director at Beaumont Hospital’s National Neurosurgery Centre as saying: “This year, we have treated 36 patients with head trauma as a result of a road traffic collision. The typical profile of our head trauma patients is young adult males. Of those, 13 were cyclists; none of them were wearing helmets. We also saw 10 drivers, 7 pedestrians and 5 motorbike riders.”

So, cyclists are clearly the worst off? And helmets matter? It’s not that straight forward.

In Ireland, the National Report on Traumatic Brain Injury in the Republic of Ireland 2008 (aka Phillips Report) gives an insight into acquired brain injury hospital admissions in the country. The report is based of data from patients presenting to hospitals in cases where the treating physician deemed sufficiently serious to warrant neurosurgical opinion.

The report has a few notable mentions of cyclists, including: “Severe Traumatic Brain Injury in pedal cyclists is low (13%) despite having less protection than people in vehicles as they are slower and energy transfer is less” and that while they recorded around half of cyclists not wearing helmets, there was “no statistical difference in injury severity was proven” between cyclists wearing and not wearing a helmet.

The data provided shows that moderate traumatic brain injury is also low among cyclists. Cyclists as a group are unique in having the vast bulk of injuries (76%) in the “Mild” category. And, again out those who sustained a brain injury, cyclists by far had the lowest irreversible injury rate and the lowest  mortality rate — in both cases, starkly so. For example, the irreversible injury rate was at just 3% compared to 16% pedestrians and the mortality rate was 7% compared to 17% for pedestrians.

If you have started crossing, spotting the tram now might be too late — it’s less than a second away!

Sadly, the Phillips report is tainted in that it makes recommendation which go well beyond the scope of its finding. The report says:

“There is a perception that some patients were the ‘victim of a tragic accident’. However, many neglected to use precautionary behaviour when choosing to use protective devices; their perception of risk and their attitudes towards protective equipment influences the decision making process or changes in circumstance impairs their judgement.”

This is clearly as case of what Goldacre and Spiegelhalter refer to as a “seductively individualistic approach to risk management (or even ‘victim blaming’).”

There are less individualistic approach to risk management such as dealing with the built environment or dealing with the causes of collisions (usually drivers according to most studies we’ve seen), but in Ireland these approaches seem to be not very seductive at all. Expect in our rail safety regime.

The Railway Safety Commission and its independent Accident Investigation Unit look at the causes of collisions and near hits on the Irish rail network. If there’s a physical problem found on and around the railway, it’s fixed. We’ve only ever encountered one time where dangerous cycling infrastructure was fixed within weeks of reporting it — it was at a blind spot at a cycle path crossing over Luas tracks and thus the issue could be reported to the Railway Safety Commission. The blind spot was fixed quickly.

This is in stark contrast to the road system generally, where lamp posts, bins, and posts have remained on cycle paths for years and where the placement of traffic light posts on narrow cycle path is called standard practice by one local authority. Or where 24km of Dublin City main roads are repaved and painted with narrow, sub-standard cycle lanes apparently just because the new guidelines which were already published were not officially signed.

In the Netherlands, local authorities take a Railway Safety Commission type approach to collisions. As the Boston Globe reports: “In the Netherlands, accidents like these are followed by intense investigations, street redesign, and criminal prosecution on a level wholly different from Boston, where a slew of bike fatalities in recent years have prompted modest on-street changes and police crackdowns on bicyclists running red lights. But there have been few street design overhauls and no criminal convictions of motorists in those fatal accidents.” We’re clearly closer to Boston here.

…Less than a full second later.

The newspaper goes on to say: “The immense dedication of resources reflects a wider attitude in the Netherlands, experts say, that bike accidents are a preventable public danger.”

The Irish Rail Accident Investigation Unit also looks at the causes of incidents and if, for example, human error is at fault from a train driver or train or track maintenance perspective, they’ll focus fixing the source of those issues which cause the incidents. They won’t dismiss these things and then turn around and suggest that passengers wear protective gear. But this is effectively the main focus of road safety — the potential victims should chance their behaviour.

Looking at the wider picture — as Goldacre and Spiegelhalter do — shows how helmets put people off cycling can result in less people cycling; so the injury rate might look better, but less healthily outcomes are shifted elsewhere. Such as to the wider obesity problem which happens on a larger scale. We have also covered the safety in numbers effect in Dublin — where more cyclists equals less deaths and injury.

Road safety needs the full facts in the right context, not stats out of context or half facts which suit the media campaigns of the RSA. Cycling safety needs more than that “seductively individualistic approach”. We need a population health approach, not doctors from one isolated area looking at their issue in isolation regardless of what affects that has elsewhere.

MORE: Phillips Report (PDF)


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