According to US Department of Transportation (DOT) estimates, there are 2.5 million heavy trucks (those with gross weight above 26,000 lb) in the US Trucks carry three-quarters of the value of freight shipped in the US and two-thirds of the cargo weight. Trucks in the US moved more than 6.2 trillion and 7.8 billion tons of manufactured goods and raw materials respectively in 2002, according to DOT (2005). Traffic hazards associated with truck operations on the highway are well documented and are not addressed, as this article focuses on driver and helper falls from trucks while parked. Safety regulations likely have a lesser impact on the safety and health of long-haul truck drivers because of jurisdictional issues that fragment applicable authority between DOT and OSHA. A huge number of trucks operate on US highways and it appears almost certain that a substantial fall risk is present when drivers/helpers climb on truck trailers and loads to perform tasks with no fall protection and often no assistance.