Estimated Effects of Repealing Michigan's Mandatory Helmet Law: 2007 Update
The Office of Highway Safety Planning has been asked to update an April 2004 analysis of the estimated effects of repealing Michigan's mandatory helmet law. That analysis estimated a 26% increase in motorcyclist fatalities, a 17% increase in incapacitating injuries, and a 20% increase in economic costs in the event of a repeal. Two things have changed since then:
Michigan has seen an increase in the number of motorcyclists, motorcycle crashes, and motorcycle fatalities, thereby increasing the number of motorcyclists potentially affected by a repeal; Louisiana, the state seeing the highest increase in post-repeal motorcyclist deaths, re-instituted its mandatory helmet law.
A higher baseline for fatalities and crashes means that applying the same percentage increase will produce a larger impact. The expected effects of a repeal are now larger than they were in 2004. From 2005-2006, Michigan motorcyclists annually suffered 116 fatalities, 746 incapacitating injuries, 2,057 other injuries, at a total economic cost of $628 million. If Michigan's mandatory motorcycle helmet law were to be repealed, the state should expect to see an annual increase of at least 30 fatalities, 127 incapacitating injuries, and $129 million in economic costs. This estimate is based solely on decreased helmet use and does not include any increases in motorcycle use. If motorcyclists are expected to ride more miles without helmets or new motorcyclists are expected to start riding, these estimates should be multiplied to include that increase. Notably, new motorcyclists will have more crashes per mile or hour of riding, and therefore a disproportionate impact on crash totals, even if they have a (secondary) requirement to wear helmets.
The authoritative report on motorcycle helmet effectiveness remains Motorcycle Helmet Effectiveness Revisited, which estimates that motorcycle helmets are 37% effective at preventing motorcycle fatalities. This comes from actual crash outcomes involving motorcyclists wearing helmets or not, not on theoretical or design-based analysis.
Researchers at the University of Michigan trauma center found that hospitalized unhelmeted motorcyclists had average care costs of $37,317 (20% higher than helmeted motorcyclists) and were 6% less likely to have insurance.