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Policy statement

Helmet laws: California

Introduction and scope

California introduced a statewide helmet law for children and youths under 18 years old from 1st January 1994. There had been a helmet law since 1987 for cycle passengers aged under 5 years.

Compliance and enforcement

There is no statewide helmet use data.

Helmet use by cyclists under 18 in San Diego increased and then fell again as follows (Ming, Gilchick and Bender, 2006):

1992 1993 1994 1995 1996

The subsequent fall in helmet use may be because enforcement of the law was lax.

During 1994 only warnings were given to cyclists not wearing a helmet. From 1st January 1995, offenders or their parents have been liable to a fine of USD 25 upon citation. However, the fine can be waived for a first offence.

Effect on casualties

A statewide study (Lee, Schofer and Koppelman, 2005) suggested a decreased risk of head injury for some groups of youth cyclists but not for others. However, with no information on exposure or helmet use, this study is weak and contradictory.

A study based in San Diego (Ming, Gilchick and Bender, 2006) found no significant reduction of serious head injury rates as a result of the legislation. Indeed, the percentage of cyclists with serious head injuries rose from 27.2% in the pre-law period to 28.2% post-law, despite an increase in percent helmet wearing, and the highest increase in serious head injuries (from 59 to 71 per annum) coincided with the fastest growth in helmet wearing (1992-93).

Effect on cycle use

Hospital data for non-head injuries suggest that across California youth cycling declined by around 14% as a result of the law (Lee, Schofer and Koppelman, 2005).

Cost benefit

No analysis.


Lee, Schofer and Koppelman, 2005

Lee BH, Schofer JL, Koppelman FS, 2005. Bicycle safety helmet legislation and bicycle-related non-fatal injuries in California. Accident Analysis & Prevention 2005;37:93-102.

Ming, Gilchick and Bender, 2006

Ming J, Gilchick RA, Bender SJ, 2006. Trends in helmet use and head injuries in San Diego County: The effect of bicycle helmet legislation. Accident Analysis & Prevention 2006;38(1):128-134.

See also