## 2 Study Areas  
The national and local governments in Korea have implemented various policies, e.g., EV purchase incentives, construction of charging infrastructure, free parking, and designated parking spaces for EVs, to promote EVs, resulting in a rapid increase in domestic EV registration (88.1% of annual growth rate, with 2775 EVs registered in 2014 and 231,443 in 2021) [24]. In particular, some regions in Korea, such as Seoul and Jeju-do, are exemplars of successful cases that have promoted EVs with the local government's massive investments in constructing EV charging infrastructure. In Jeju-do, a total of 1821 charging stations have been installed (including 1672 slow-charging stations and 149 fast-charging stations), and the density of charging stations is estimated to be approximately 0.984 stations/km\({}^{2}\) (1821 stations in the Jeju-do area of 1849 km\({}^{2}\)) (Figure 1b). The density of EV charging stations in Jeju-do is the highest among the regions in Korea. The Jeju-do government's massive investment in constructing charging infrastructure appears to encourage EV adoption. In 2018, the number of EVs sold in Jeju-do (7185 EVs) accounted for 22.6% of the total domestic sales (31,696 EVs), which is a significantly high rate considering that the population of Jeju-do (around 700 thousand) accounts for only 1.3% of the total population of Korea (around 51.7 million).  
EV penetration is relatively low in Korea, except for some successful regions. For example, Gangneung-si, a relatively small city in Korea (with a population of approximately 210,000), is lagging behind in the EV program, compared with other regions. Investments in the construction of charging infrastructure in Gangneung-si also appear to lag behind some successful regions. As of 2021, the density of charging stations in Gangneung-si is  
Figure 1: Geographical distribution of the EV charging stations in the study regions: (**a**) study areas; (**b**) stations in Jeju-do; (**c**) stations in Gangneung-si.  
only 0.123 stations/km\({}^{2}\) (114 slow-charging stations and 14 fast-charging stations; the city area is 1040 km\({}^{2}\)) (Figure 1c). The low investment in charging infrastructure appears to have led to a low EV penetration rate in Gangneung-si. Unfortunately, information on the number of EVs sold in Gangneung-si has not been reported; however, it is estimated that EV sales in Gangneung-si are significantly lower than those in successful regions in Korea. Gangneugn-si recently announced plans to promote EVs, including EV purchase subsidies and expansion of EV charging infrastructure. However, some obstacles to the promotion of EVs still exist, primarily because of the insufficient budget. Therefore, a strategy for constructing efficient charging infrastructure is required for small cities; in other words, the lessons learned from successful regions may help small cities identify optimal charging locations to cost-effectively construct charging infrastructure. To this end, Jeju-do (maturity phase of the EV program) and Gangneung-si (early phase of the EV program) were selected as case studies, and a comparative analysis of the charging demand in these regions was conducted to investigate the factors driving different charging patterns by region.