Vision Zero is a multi-national road traffic safety project that aims to achieve a highway system with no fatalities or serious injuries involving road traffic. It started in Sweden and was approved by their parliament in October 1997. A core principle of the vision is that 'Life and health can never be exchanged for other benefits within the society' rather than the more conventional comparison between costs and benefits, where a monetary value is placed on life and health, and then that value is used to decide how much money to spend on a road network towards the benefit of decreasing how much risk.
Vision Zero is based on an underlying ethical principle that "it can never be ethically acceptable that people are killed or seriously injured when moving within the road transport system." As an ethics-based approach, Vision Zero functions to guide strategy selection and not to set particular goals or targets. In most road transport systems, road users bear complete responsibility for safety. Vision Zero changes this relationship by emphasizing that responsibility is shared by transportation system designers and road users.
Vision Zero suggests the following "possible long term maximum travel speeds related to the infrastructure, given best practice in vehicle design and 100% restraint use". These speeds are based on human and automobile limits. For example, the human tolerance for a pedestrian hit by a well-designed car is approximately 30 km/h. If a higher speed in urban areas is desired, the option is to separate pedestrian crossings from the traffic. If not, pedestrian crossings, or zones (or vehicles), must be designed to generate speeds of a maximum of 30 km/h. Similarly, the inherent safety of well-designed cars can be anticipated to be a maximum of 70 km/h in frontal impacts, and 50 km/h in side impacts. Speeds over 100 km/h can be tolerated if the infrastructure is designed to prevent frontal and side impacts.
"Roads with no possibility of a side impact or frontal impact" are sometimes designated as Type 1 ( motorways/freeways/Autobahns ), Type 2 ("2+2 roads") or Type 3 ("2+1 roads"). These roadways have crash barriers separating opposing traffic, limited access, grade separation and prohibitions on slower and more vulnerable road users. Undivided rural roads can be quite dangerous even with speed limits that appear low by comparison. In 2010, German rural roads, which are generally limited to 100 km/h (62 mph), had a fatality rate of 7.7 deaths per billion-travel-kilometers, higher than the 5.2 rate on urban streets (generally limited to 50 km/h (31 mph)), and far higher than the autobahn rate of 2.0; autobahns carried 31% of motorized road traffic while accounting for 11% of Germany's traffic deaths.