ABSTRACT
<p><b>PURPOSE</b>The aim of this present study is to investigate the prevalence of alcohol and substance abuse (ASA) and its relationship with other risky driving behaviors among motorcycle drivers.</p><p><b>METHODS</b>This is a cross sectional study which is performed at Shiraz city of Iran. Data from motorcycle drivers were collected using a standard questionnaire in eight major streets at different times of the day. The data includes consumption of alcohol and other substances two hours before driving and some of the risky behaviors during driving.</p><p><b>RESULTS</b>A total of 414 drivers with a mean ± SD age of (27.0 ± 9.3) years participated in the study. Alcohol or substance consumptions two hours before driving was significantly associated with risky driving behaviors such as using mobile phone during driving, poor maneuvering, and driving over the speed limit (both p < 0.001). It was also associated with carelessness about safety such as driving with technical defects (p < 0.001) and not wearing a crash helmet (p=0.008).</p><p><b>CONCLUSION</b>Screening for alcohol and substance consumption among motorcycle drivers is an efficient way to identify drivers that are at a greater risk for road traffic accidents.</p>