This study aimed to analyze the impact of implementing a voluntary driver's license return program on reducing traffic crashes for older drivers who were previously involved in traffic accidents. The traffic crashes caused by elderly drivers were categorized by crash type. We used the Chi-square test to compare municipalities that implemented the program in 2019 and 2020 with those that did not and explored variations in crash types based on the residential areas and age groups of elderly drivers. The voluntary driver's license return program reduced considerably the number of single-vehicle crashes involving elderly drivers. Moreover, while all crash types decreased in rural areas, only pedestrian–vehicle, and single-vehicle crashes were reduced considerably in urban areas. In terms of age groups, drivers aged >75 years were associated with reduced numbers of crashes (all types). Similarly, the 70–74 age group demonstrated considerable reductions in pedestrian–vehicle and single–vehicle crashes, emphasizing the importance of encouraging and supporting license returns among these age groups. First, because the characteristics of each crash type vary, it is important to analyze the impact of voluntary driver’s license returns on crash reduction, with a focus on specific crash types. Second, voluntary license returns should be promoted in all regions. However, in rural areas with limited access to public transportation, mobility must be supported by the introduction of DRT. Third, given that drivers aged >75 years were associated with reduced numbers of crashes (for all types of crashes), priority policies should be implemented to encourage license returns within this age group, along with tailored incentives. However, as the voluntary license return program is intended to support selfinitiated cessation of driving without compulsion, strategies should also be explored to promote voluntary returns without age restrictions. Fourth, a standardized evaluation system should be established to enable older drivers to assess their driving abilities and physical conditions, further encouraging voluntary license returns.

The present study was conducted to investigate the public awareness level of the Korean population on the hazards of radon. Its purpose was to serve as a preliminary study for the development of a risk communication program suited to Korean domestic conditions. An in-house developed questionnaire was used as an awareness surveying tool. Five thousand people (adults) from the general population, randomly selected regardless of their age, academic background, income level, and regional distribution were surveyed. The survey was conducted between December 2015 and February 2016, and completed in a self-reporting format. The survey results showed that public awareness of the radon risk was very low, as indicated by more than roughly 85% of the respondents saying that they did not know what radon was. Moreover, survey results for those who knew what radon was showed a very low level of awareness regarding the physical properties and hazards of radon. Through the findings of the present study, it was confirmed that the awareness of radon hazards among the residents of Korea needs urgent improvement and that the development of a radon risk communication program accounting for age, income, region, occupation, and various information delivery routes is also needed.