Throughout Peter Calthorpe's decade-spanning career in urban design, planning, and architecture, he has developed and practiced the key principles of New Urbanism: that the most successful places are diverse in uses and users, are scaled to the pedestrian and human interaction, and are environmentally sustainable. Calthorpe developed the concept of Transit Oriented Development, a strategy that is now the foundation of many regional policies and city plans around the world. His work internationally has demonstrated that community design with a focus on environmental sustainability and human scale can be adapted throughout the globe. Most recently Calthorpe launched the urban-planning software UrbanFootprint which models the diverse impacts of urban planning scenarios for designers and planners working for cities, businesses, public agencies and nonprofits.