Trying to deny that the helmet law reduces cycling

Abstract

Cycling was rising in Australia by 10% per year until the helmet law. Afterwards, it dropped by 30%.
A government commissioned “study” has misrepresented a bicycle rally as a revival in cycling.

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Bicycle travel in Australia was increasing by 10% a year from 1986 to 1989, before the helmet law. After the helmet law, surveys showed cycling declined by 30 to 40%. An independent assessment estimates that cycling was 50% below previous trend by 1996.

The Victorian government commissions studies defending its policies through organisations like the Monash University Accident Research Centre (MUARC). MUARC has published studies claiming the helmet law had reduced head injuries. Such “studies” use biased statistics, resulting in misleading claims defending the legislation.

MUARC conducted this study, claiming that adult cycling recovered two years after the helmet law.

According to the study, child cycling dropped 30% but did not recover.

MUARC_count_child_cyclists

Yet adult cycling appeared to recover.

MUARC_count_adult_cyclists

Why would adult cycling recover but not child cycling?

A bicycle rally passed through one of the counting site in 1992. At that site, there were 451 cyclists in 1992, versus 72 in 1991.

The study authors knew about the bicycle rally. Yet they included it in the study, claiming:

“Another explanation for some of the increase in bicyclist numbers in 1992 is related to the fact that there appears to have been a bicycle rally passing through one of the sites …

From a statistical point of view, however, an occurrence such as this is a true observation, well within the bounds of “normal” behaviour for that time period, and cannot be excluded from the analysis”

The whole point about those comparisons is to keep everything else the same. Same sites, same observation periods, same time of year, so that noise does not distort observations.

The site with the bicycle rally showed a 6 TIMES increase. This is not “normal behavior”. It distorts the results. Yet the study authors chose to include it. This misrepresents a bicycle rally as a revival in cycling.

 

A recent “study” commissioned by the Queensland government claims:

 “In Melbourne adult cyclist numbers doubled after the helmet legislation”.

, quoting the study mentioned above. How they arrived at this conclusion is a mystery. This “study” was edited several times by the Queensland department of transport.

The fundamental role of science is to serve the truth.
It is NOT to serve the interests of the state.

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