Security of hazardous materials (hazmat) shipments is a growing concern for many governments and private companies due to their potential use as weapons. This paper identifies a methodology for obtaining the paths taken by a malicious entity when he/she hijacks a hazmat truck based on conditional consequence and a measure of cost (either distance or travel time). The work compares the routes obtained by travel time and distance for a sample network and suggests the need for travel time to be considered in urban areas, especially in peak hours.