The role of trucks in rounding up alleged Indonesian Communist Party (Partai Komunis Indonesia, PKI) members and other targets, transporting them to jail or to their execution, and disposing of their bodies is a recurring theme in anecdotal accounts of Indonesia’s 1965–66 massacre (Thirtieth of September Movement). This paper explores the connection between the presence of transportation infrastructure (roads and trucks) in the various kecamatan (districts) of East Java and estimates of kecamatan-level population change associated with the violence during 1965–66. Two questions are answered. First, was the transportation infrastructure simply incidental to the process, or did it materially shape the scale and scope of disappearances, killings, and movements of people? Second, how did the means of transportation impact whether people were disappeared, killed, or moved around? Using actual census data, the analysis demonstrates that kecamatan which were more exposed to the road network tended to experience larger losses in population than those that were less exposed. The widespread use of trucks is also consistent with systematic army involvement in the killings across the province. A list of kecamatan that were disproportionately exposed to the road network and that experienced heavy losses in population is provided.