Road traffic accident is one of the 10 most important problems facing the world. Each year, some estimated 1.3 million fatalities, and up to 50 million injuries occur on the world’s roads with tragic human and economic consequences. For Thailand, in 2008 the economic and social costs of road crashes amounted to 243,000 million Baht (~2.8% GDP). Around 12,000 deaths occurs annually on Thailand’s roads, of these, about 82% are deaths relating to the use of motorcycles. The road crash problem and its dire consequences are well known, however, the causes of the crashes and injuries are far from certain. This paper describes an investigation into the causes of motorcycle crashes with the goal of making the road system safer for the motorcycle users. The human element, the infrastructure and the vehicle element in the road system are examined. An overview of the motorcycle crash situation in Thailand is given. A detailed case of motorcycle crash is described. The case involves a young rider and his passenger whose scooter was hit by a trailer. The innocent victims with their inadequate riding skill and traffic knowledge and the high risk behaviors of some victims such as riding at high speed, not wearing crash helmet, driving while drunk, appear to have compounded the already dangerous situation for them, where they have to regularly use the same road space with automobiles, buses and trucks which often, travel at high speed.