The last few years have witnessed a steadily increasing growth in the sales and use of three and four wheel all-terrain recreational vehicles (ATVs). These vehicles are promoted for off-road use and are operated in widely varied environments ranging from dry desert surfaces to wet hilly wooded areas of the country. The design of the ATV and its intended purpose make it an attractive vehicle for a large cross-section of the general public. The general appearance of the vehicle suggests a relatively simple and safe means of transportation, even in environments which have heretofore had limited accessibility.However, it appears that the design and operational characteristics of these vehicles require more of a driver than he may initially assume as evidenced by the number of injuries and deaths that have occurred. How can the number of deaths be reduced and the severity of injuries be lessened? The intent of this paper la to address these questions by focusing on occupant protection for the driver by means of a rollover protective structure (ROPS) and a seat restraint system.These questions are addressed by: analyzing accidents which have occurred to understand how ATV injuries and deaths occur, applying existing technology and knowledge of HOPS and restraint systems on other vehicles, using creative engineering in the application of this knowledge, and determining the safety tradeoffs, if any.A ROPS and a seat restraint system (patent pending) were developed for a four-wheeled ATV without any apparent degradation of the ATV stability and maneuverability. The addition of the seat restraint system by itself appears to greatly enhance the ability to ride the vehicle by providing body support for various operating positions. However, from a safety standpoint a ROPS must accompany the incorporation of the seat restraint system.