The successful city of the 21st century will be replete with choices, including non-motorized, post-fossil fuel travel options. Citizens of the world do not want to sit in bumper-to-bumper traffic. They do not want to walk in mud, nor feel threatened on a simple bike ride. They want to be in cities that provide for creative interaction, affordable living and healthy movement. These principles will help achieve that end.




Great cities start with great pedestrian environments. Walking is the most universal form of transport and when streets are designed to prioritize pedestrians, health, economic activity and safety all improve. Walkable streets are the fundamental building blocks of a sustainable city.


Sustainable transit will not be viable unless it connects people to attractive places that encourage them to stay. Making a street “great” includes having a diversity of places and activities along it. Lively downtowns stack retail on the ground floor, with residential and office space above. Shops and offices are supported by the people who work there by day and by the people who live there at night, helping to create a vibrant street life.


Bicycles and other means of people-powered transport, like pedicabs, allow for the convenience of door-to-door travel, but use less space and fewer resources. They are the healthier and more sustainable alternative to cars and taxis for short trips. To encourage their use, riders first need to feel safe, and in general, the more bicycles on the streets, the safer they become. This also requires slowing down traffic and providing high-quality dedicated space, like bike lanes.


By 2030, cities are projected to absorb 2 billion more people. High density is crucial to low-carbon cities. Density needs to be related to the capacity of all modes of transportation. If roads are designed to be bike and pedestrian-friendly and transit priority lanes on major arterials, activities like shopping, working and day care can be co-located to make walking, cycling and mass transit more convenient than driving. This will shorten trip distances, save travel time, and preserve millions of square kilometers of arable land. These dense communities use resources more efficiently, reducing the carbon footprints of its residents.


Cities that are pleasant to walk and bicycle through typically have large numbers of narrow, short streets and many intersections. This makes the traffic slow down while walking becomes more direct, varied, interesting and attractive. Streets that are short and relatively narrow are also well-scaled to the perception of people on foot. Buildings, shops, trees and other streetscape elements are closer to the pedestrians and cyclists as they travel, increasing the vitality of local retail.


Community location has a long-term impact on sustainability. New developments placed far from existing cities are inconvenient and rarely thrive. City planners can avoid this by locating compact new sub-centers within or adjacent to existing cities. In addition to protecting arable land, this strategy significantly decreases the cost of providing transit, utilities, and other services to these new locations, while reducing most residents’ daily commute.


Some trips are too long to make walking or cycling a viable option in our growing cities. Comfortable, safe, high-speed public transit can move millions of people quickly and comfortably using a fraction of the fuel and space required by automobiles. Bus-based mass transit systems like bus rapid transit (BRT) have often proven to be a cost effective, high quality solution, combining the efficiencies of metro systems with exclusive bus lanes and clean new buses.


Even in 2030, some trips will still be made by car. But more cars will mean more congestion, pollution and time on the road unless traffic is managed better. This includes what many cities are doing now: using parking and congestion charging to encourage people to leave their cars at home, eco-zones where only clean vehicles can enter, and removing highways in favor of community revitalization.

This is excerpted from Our Cities Ourselves: Principles for Transport in Urban Life, a collaboration between the Institute for Transportation and Development Policy (ITDP), Gehl Architects and Nelson Nygaard, and a companion to the ITDP “Our Cities Ourselves” program.