https://www.selleckchem.com/products/ver155008.html The U.S. experience with motorcycle helmets affords an important insight into the responses of adolescents to age-specific laws. Political contention has led to a number of U.S. state law changes back and forth between universal and age-specific laws. Because both kinds of law require adolescent motorcyclists to wear helmets, relatively few studies have focused on how the law type affects their behavior. Differential behavior is tested by a systematic review of literature, leading to a meta-analysis, in relation to the experience of various states' motorcycle helmet laws. An electronic search was conducted for before-and-after studies in U.S. states that include data on adolescent helmet usage - both with a universally applicable motorcycle helmet law, and with an age-restricted law (usually, under-21 or under-18) - from observational, injury or fatality records for a certain period (e.g., 12 months) pre and post the state law change. The search yielded ten studies, including two that compared a set of two-thirds of adolescent noncompliance with age-restricted motorcycle helmet usage laws disappears with universal applicability. Evidence from numerous international studies of youth reaction to helmet laws suggests that a large part of the greater compliance with universal laws is due to their conveying a more convincing message that helmets afford protection against injury. Practical Applications The meta-analysis provides fresh, young-rider perspective on the continuing debate over motorcycle-helmet laws. Broader insight into adolescent psychology suggests considering alternatives to age-restricted laws more widely in safety and health policy. This research aims to investigate the perceptions and reactions of drivers regarding freeway merging situation, utilizing a new approach with the basis of a multilevel simulation platform which incorporates virtual reality (VR) technology. A VR driving environment integrated