Randomized trial of an official contact letter intended to increase proper licensure among unlicensed motorcycle owners

• Treatment resulted in more licensed owners (14.5%) compared to control (10.4%).
• The majority (85%) of contacted owners remained unlicensed nearly 3 years later.
• Crash and violation rates were equivalent across treatment and control groups.
• Other jurisdictions should consider this strategy to increase motorcycle licensure.

BackgroundApproximately one-third of all fatality-injured motorcycle operators in California from 1999 through 2008 were not properly licensed to ride a motorcycle at the time of the crash. In availing themselves of a licensing system, motorcyclists are afforded the opportunity to acquire and demonstrate the minimum knowledge and skills necessary to operate motorcycles on public roadways, and licensing allows agencies to monitor their riding performance and apply appropriate sanctions, with the overall goal being enhanced safety. To that end, a randomized trial was conducted of an intervention recommended by the National Highway Traffic Safety Administration to increase proper motorcycle licensure.MethodsOfficial contact letters providing information about obtaining a motorcycle license, and the potential legal consequences of riding without one, were mailed to owners of currently-registered California motorcycles who were not licensed to ride motorcycles. Half of the 65,766 improperly licensed California motorcycle owners identified were randomly assigned to be mailed the contact letter while the remainder served as a no-letter control group. The groups were compared on 33-month post-treatment motorcycle licensure rates and 18-month post-treatment motorcycle crashes and traffic violations.ResultsWhile a modestly higher percentage of motorcycle owners who were mailed the contact letter became properly licensed (14.5%) than those who were not mailed the letter (10.4%), the majority (85.5%) remained improperly licensed to operate a motorcycle 33 months later. The effect of the contact letter was influenced by owner age, whereby the odds of licensure for those to whom the letter was sent increased significantly for owners aged 20–34 (21%), 35–54 (47%), and 55 and older (96%). No 18-month post-treatment differences in motorcycle crash involvements or traffic violations were found.ConclusionGiven the traffic-safety neutral outcomes and relatively low cost of treatment, official contact letters should be considered in other jurisdictions to increase proper motorcycle licensure as recommended by the National Highway Traffic Safety Administration. Future letters may be more effective if they are tailored to the demographic characteristics (e.g., age and sex) of the owners.