Abstract: This report describes the development of a Geographic Information System (GIS) that models the patterns of travel of self-drive visitors to desert Australia. The VRUM™ system (Visualising Relatively Unpredictable Movement) depicts road segments used, overnight stop locations and direction of travel. At completion of the initial development stage, the system was populated with data covering travel in the period 2000–2006. This report is concerned with the user needs and logical specifications of VRUM™. It includes some description of the technical specifications, but details thereof remain commercial in confidence and are proprietary to the Desert Knowledge Cooperative Research Centre. The report also includes some examples of analysis of VRUM™ output. Aspects of the report have been published elsewhere in Holyoak and Carson 2009, Holyoak et al. 2009 and Chewings et al. 2007.