Cities are responsible for about 70% of all greenhouse gas emissions and road transportation accounts for about a quarter of those emissions. Furthermore, hours wasted in traffic congestion costs Europe €110 billion per year. These costs, in addition the air pollution-related health issues, add up to several hundred billion euros per year. And most importantly, 20,000 people die annually in accidents on European roads, about 40% of which occur in cities and 50% at intersections.