A Spatial Accessibility Study of Slow Charging Infrastructure for Electric Vehicles: Case Study in a Belgian Mid-sized City

Among all alternative vehicle technologies and advanced fuels, electric vehicles are the ones with the largest potential in mitigating climate change and improving urban air quality. Considering that the lack of public charging infrastructure is an often mentioned disadvantage of electric cars, if adequately placed, the rollout of charging stations would arguably promote the uptake of battery electric vehicles. Bearing in mind that panel interviews have indicated electric car owners to favour home charging, it should be noted that urban settings may also provide limited home charging options due to the prevalence of terraced housing and the according scarcity of garage accesses. Moreover, considering the high population density and variation thereof between city districts, optimal placement of slow public charging infrastructure constitutes an important challenge. In this context, a methodology is needed to assess the efficiency of both current and future placement of slow charging infrastructure in providing public overnight charging solutions. Few studies exist that evaluate placement strategies of existing charging infrastructure networks, but rather concentrate on optimal future location scenarios. Moreover, these optimality scenarios are often based on particular travel behaviour patterns and preferences. Yet, in the assessment of likely travel behaviour patterns, an often made implicit assumption is the ubiquitous availability of home charging. The present study therefore also adds to the current literature by addressing this widespread assumption, i.e. deliberately focusing on the application of public charging infrastructure as a substitute to home charging. As placement evaluator, a potential accessibility measurement is therefore used to map the accessibility of the currently existing charging infrastructure for each address point (e.g. households) in a mid-sized Belgian city, Ghent. In attributing accessibility scores to the different address points and considering the intended use of the infrastructure as substitute to private charging, the method takes into account: supply of, competition for and distance to the accessible charging stations. The results show a high variability of potential accessibility among population points, which indicates an unequal access to public slow charging stations. Moreover, the maps illustrate that current placement was not made to maximize residential service reach nor take into account existing private recharging options. To conclude, it is suggested that future charging network development plans should be based on an equal accessibility to slow charging for the highest number of households.