Objective We present a first test using a smartphone time use survey app for whether the risk of criminal victimization is higher while traveling than during other activities, and assess risk heterogeneity between public transport, private transport by car, and private open-air transport. Methods A sample of 1334 young adults completed a time-use survey on their smartphones with additional items on criminal victimization. Participants reported their time use and victimization experiences (vandalism, theft, threat, or assault) per 10-min timeslot for 4 days. To prevent potential confounders from affecting the results, we analyzed the data with a fixed effects logit model that exclusively relies on within-person variation between timeslots. Findings A total of 78 victimization situations were reported by 45 participants. Although these numbers are too low to draw definitive conclusions, with respect to the four types of victimization measured, sleeping appeared to be the safest activity. The risk of victimization was considerably larger during travel, but also during many other activities. We found shopping to be the activity with the highest risk of victimization. No victimization was observed during private transport by car, but the risk of victimization was significantly higher in private open-air and public transport than during sleep. Conclusion Using a state-of-the-art instrument and a rigorous statistical design, we tentatively conclude that the risk of criminal victimization is not higher during travel than during most other activities, only sleeping is safer. Larger samples are needed to assess the robustness of our findings. We discuss practical implications, strengths and weaknesses of the study, and new research challenges.