The assumption can be made that car occupants will use their seatbelts (of course, encouragement and enforcement will be needed to achieve this). In many cities in Europe it is now the norm to have 30 km/h speed limits on residential roads, but it is still common to have the speed limit on urban arterials set to 50 km/h. Serious and fatal accidents with pedestrians tend to occur precisely on those urban arterials. Yet these roads also have intersections where serious and fatal crashes are often concentrated.