Paper Title
Causal Model Of Motorcyclist Helmet Use Behavior In Iran: Pls-Sem Approach

Abstract
Despite the cumulating evidence regarding the effectiveness of helmet use by motorcyclists in reducing fatalities and severe injuries, helmet usage remains low among Iranian motor riders. In fact, Iran has the fifth highest road traffic fatality rate across the world. However, identifying the factors affecting the use of helmets by motorcycle riders is of great interest, due to the increasing number of 2-wheel motorized vehicle fatalities worldwide. This study examines the factors affecting motorcyclist helmet usage, such as age, social norms, tendency for violation, difficulty in helmet use, and the number of fines issued for failed helmet use. For this purpose, a comprehensive questionnaire was developed with three questions about helmet usage (i.e., just carrying a helmet, just wearing a helmet without closing the helmet strap, and correct use of a helmet). Using a face-to-face interview method, 220 questionnaires were completed by motorcyclists. The data were analyzed with the partial least squares structural equation model (PLS-SEM) approach. The result of the total effect of age variable showed positive effects of 0.12 on the complete use of helmet with increasing the age. The social norms latent variable (being reflective of public views toward helmet usage, as well as encouragement by family and friends) had a great reducing effect on both the tendency for violations and the difficulty of helmet usage, with total effect of 0.33 on the correct use of a helmet. Furthermore, the effect of the number of fines was positive on both ―just carrying a helmet‖ and ―wearing a helmet without closing the strap,‖ while it had a negative effect on ―correct use of a helmet.‖ Keywords- Helmet use, Motorcyclist behavior, Safety, PLS-SEM