Several cities worldwide have started setting speed limits of 30 km/h in large parts of the city. Brussels, Paris and Vienna have introduced city-wide 30km/h speed limits, mixing safely traffic of pedestrians, cyclists and motorised vehicles, with significant results in reducing road crashes, emissions and noise and upgrading city liveability. Within the 30 Marathons in 30 months campaign-challenge of Prof. George Yannis, a comprehensive set of resources on cities experiences with 30km/h speed limit is made available: