If all cyclists in the Netherlands were to wear helmets in 2030, 100-110 road deaths and 1,700-1,900 serious road injuries could then be saved (MAIS3+). If half of all cyclists were to wear helmets in 2030, the savings would be 50 road deaths and 800-900 serious road injuries [32].
This estimate is based on the effectiveness of bicycle helmets as shown in Høye's meta-analysis [19] (see the question How effective are bicycle helmets in preventing (fatal) head injuries among cyclists?) combined with the prevalence of (severe) head and brain injuries among cyclists, assuming a current wearing rate of 5%. The estimate of the effectiveness of helmets has exclusively been based on international research. Considering bicycle usage and the available (cycling) infrastructure in the Netherlands, it cannot be stated with any certainty whether the effect in the Netherlands would be the same. There are, however no concrete indications for a different outcome.
Of all cyclists in the Netherlands who are seriously injured in a bicycle crash, one-third (33%) suffer head or brain injuries. In bicycle crashes involving a motor vehicle, nearly half the cyclists suffer head or brain injury (48%); in bicycle crashes not involving a motor vehicle, more than a quarter (28%) do. Figure 2 shows that serious head and brain injuries are relatively more common among young people.
Figure 2. Share of hospitalised cyclists with severe head or brain injuries (AIS 3+) by age group, relative to all hospitalised cyclists with severe injuries (MAIS 3+); average over 2014-2019 (source: Dutch Hospital Data). Do bicycle helmets also have adverse effects?
