We really have to admit that over the past 100 years we have been building cities much more for mobility than for people's well-being. Every year thousands of children are killed by cars. Isn't it time we build cities that are more child-friendly? Children are a kind of indicator species. If we can build a successful city for children, we will have a successful city for all people. When I was elected mayor of Bogot and got to city hall, I was handed a transportation study that said the most important thing the city could do was to build an elevated highway at a cost of $600 million. Instead, we installed a bus system that carries 700,000 people a day at a cost of $300 million. We created hundreds of pedestrian-only streets, parks, plazas, and bike paths, planted trees, and got rid of cluttering commercial signs. We constructed the longest pedestrian-only street in the world. It may seem crazy, because this street goes through some of the poorest neighborhoods in Bogot, and many of the surrounding streets aren't even paved. But we chose not to improve the streets for the sake of cars, but instead to have wonderful spaces for pedestrians. All this pedestrian infrastructure shows respect for human dignity. We're telling people, You are important-not because you're rich or because you have a Ph.D., but because you are human." If people are treated as special, as sacred even, they behave that way. This creates a different kind of society.