Vehicles carrying objects that are not properly secured pose a safety risk on our nation's roadways. Debris that falls from a vehicle can collide with other vehicles or pedestrians, causing serious injuries or fatalities. According to data collected by the National Highway Traffic Safety Administration (NHTSA), there were about 440 fatalities caused by roadway debris in 2010. However, the exact number of incidents resulting from vehicles carrying unsecured loads is unknown. This book examines NHTSA's data collection efforts as well as states' laws related to unsecured loads. It also discusses the extent that Pipeline and Hazardous Materials Safety Administration's (PHMSA) data reliably identify wetline safety risks; options for addressing wetline safety risks, and how well PHMSA has assessed the costs and benefits of addressing these risks through regulation.