There has been a structural change in mobility in major Spanish cities in recent decades, with a switch to the pattern followed in other countries in the area. A shift has taken place from a traditional Mediterranean model to a North American city stereotype, with uncontrolled motorization and major implications for public health. This article specifically analyzes negative road safety related externalities that result from this process, given that the trend seems to show a steady decline in road safety accidents on urban roads in Spain, with major differences among NUTS-3 provinces. The objective is to evaluate the factors that empirically explain these differences for the 2003-2013 period using a panel data analysis. Results show that a key role is played by urban development variables, such as population density and improvements in health services, with advances linked to more accessible and sustainable urban transportation, such as the Smart City concept. Not only does this article close a gap in the literature, but the findings can also serve as a practical guide for the development and implementation of urban mobility and road safety plans, and reveals the special needs of the most vulnerable groups
