AbstractBackground:Many capital cities around the world have been subjected to terrorist attacks on their transport systems with devastating consequences. Large crowds in small enclosed spaces, disruption to people movement, and the psychosocial and financial repercussions of attacks are some of the many soft target vulnerabilities of mass-transit systems.This study is an epidemiological examination of all terrorism-related events targeting air, sea, and ground transport modalities sustained from 1970-2019, comparing the rates of fatal injuries (FI) and non-fatal injuries (NFI).Method:The Global Terrorism Database (GTD) was downloaded and searched using the internal database search functions for all events that occurred from January 1, 1970 - December 31, 2019. Years 2020 and 2021 were not yet available at the time of the study. “Transportation,” “Airport and Aircraft,” and “Maritime” as primary target types were selected for the purpose of this study, and events were further sub-classified by region, weapon type used, and by suicide attack (SA). “Airport personnel” were excluded. All classifications and sub-classifications were pre-determined by the GTD.Results:There were 8,729 transportation-related (air, sea, and ground) attacks documented during the study period with 19,020 fatalities and 45,218 NFI. This accounted for 5.2% of all terrorist attacks (168,003 total events), 5.6% of all FI (total 339,435), and 9.1% of all NFI (total 496,225). The mean FI was 2.2 per event and the mean NFI was 5.2 per attack.South Asia (28.4%), Middle East and North Africa (18.2%), and South America (14.9%) accounted for 61.5% of all transport related attacks. Attacks on subways inflicted a disproportionately high 51.5 NFI per attack. Suicide attacks recorded the highest ratios for both FI (13.71 per attack) and NFI (139.00 per attack).Conclusion:Transport modalities are vulnerable terrorist soft targets. The repercussions of attacks on public transport modalities represent a significant and unique psychosocial and economical risk to the affected communities. Suicide attacks on subways represent a unique and significantly higher casualty risk than other transport modalities. Risk mitigation strategies should be regularly revisited by Counter-Terrorism Medicine (CTM) specialists.