Gerasimos Balatsinos, “Cost Benefit Analysis of 30 km/h speed limit implementation in all EU cities”, Diploma Thesis, NTUA, School of Civil Engineering, Athens, March 2026.

The aim of this Diploma Thesis is to develop a Cost–Benefit Analysis (CBA) of the implementation of a 30 km/h speed limit in urban areas across the Member States of the European Union (EU). To achieve this objective, a methodological framework consisting of two distinct yet complementary stages was developed: (1) a statistical analysis of road crashes to investigate the factors influencing crash severity across EU countries, and (2) a Cost–Benefit Analysis at a macroscopic level to evaluate the implementation of a 30 km/h speed limit. Initially, road crash data recorded within urban areas for the period 2016–2022 were collected for each EU Member State, including fatal crashes as well as those involving serious and slight injuries. For each road crash, additional variables were considered for the year 2022, including demographic characteristics (gender and age), mode of transport and external conditions (temporal, weather, and lighting conditions). Subsequently, the data was utilized to develop two logistic regression models, incorporating fixed and random effects. The results indicate that crash severity is primarily influenced by the type of transport mode, lighting conditions, and age, while other factors exhibit a smaller yet statistically significant effect. Furthermore, substantial variation is observed across EU countries in terms of baseline risk levels. Following this, a CBA was conducted at a macroscopic European level to assess the socio-economic feasibility of implementing a 30 km/h speed limit. The analysis was carried out both individually for 25 European cities that have already implemented the measure and collectively at the European level, with a time horizon spanning from 2016 to 2034. The estimation of benefits accounts for reductions in fatalities, serious and slight injuries, fuel consumption, and carbon dioxide (CO₂) emissions. Costs include initial investment costs, operating costs, and travel time impacts. The findings suggest that the implementation of a 30 km/h speed limit constitutes an economically feasible measure at the European level, yielding a positive Economic Net Present Value (ENPV) of approximately €18 billion. At the city level, the ENPV ranges from approximately €90 million (Paris) to €4.6 billion (London).