Vision Zero is a road traffic safety project started in Sweden in 1997 which aims to achieve a highway system with no fatalities or serious injuries in road traffic. 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 approach where a monetary value is placed on life and health which is then used with a Benefit-cost ratio evaluation before investing money in the road network to decrease risk.^{[citation needed]}

Vision Zero is based on four principles:

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.

Bill de Blasio is a New York City elected official, holding the citywide office of New York City Public Advocate, which serves as an ombudsman between the electorate and the city government. De Blasio previously served as a New York City Council member representing the 39th District in Brooklyn (Borough Park, Carroll Gardens, Cobble Hill, Gowanus, Kensington, Park Slope, and Windsor Terrace).

As Public Advocate, de Blasio is first in line to succeed the New York City Mayor.

De Blasio was then elected to the New York City Council in 2001, and was subsequently re-elected in 2003 and 2005 to represent District 39, which includes the Brooklyn neighborhoods of Borough Park, Carroll Gardens, Cobble Hill, Gowanus, Kensington, Park Slope, and Windsor Terrace. In the Council, de Blasio chaired the Committee on General Welfare, and is a member of the Education, Environmental Protection, Finance, and Technology in Government Committees.

In 1999, De Blasio was elected a member of Community School Board 15.