Source: Smart Growth Online
Transit-oriented development, or TOD, is a type of community development that includes a mixture of housing, office, retail and/or other amenities integrated into a walkable neighborhood and located within a half-mile of quality public transportation. In the United States, a half-mile-radius circle has become the de facto standard for TODs because it corresponds to the distance someone can walk in 10 minutes at 3 mph and is a common estimate for the distance people will walk to get to a rail station. A TOD typically includes a central transit stop (such as a train station, or light rail or bus stop) surrounded by a high-density mixed-use area, with lower-density areas spreading out from this center. In turn, this district contains specific features that are designed to encourage public transport use including mixed-use development that will use transit at all times of day, excellent pedestrian facilities such as high quality pedestrian crossings, narrow streets, and tapering of buildings as they become more distant from the public transport center.
Many studies have looked at the benefits of TODs, one of the most important being the great efficiency of land and roads, and huge transportation and tax savings for residents. Development around transit promotes compact development, multiple rather than single uses, a pedestrian orientation, and attention to civic uses. Successful development around transit also demands a new form of community building that not only supports and encourages transit use but also transforms the surrounding area into a place that is so special and irresistible that people will invest there, live there, and visit again and again. To make informed decisions about TOD, research institutions and governments have developed a variety of methodologies that can help identify which station areas are good candidates for TOD, determine what level of density the area around a given station can absorb, and figure out what kind of development mix makes sense in a particular area, looking to strike the right balance between jobs, housing, and other amenities.
The Washington Post | "Expect to see more transit-oriented housing in the future"
Environmental Protection Agency | Encouraging Transit Oriented Development: Case Studies That Work
The World Bank | Transforming the Urban Space Through Transit-Oriented Development: The 3V Approach
Reconnecting America | What is TOD?
The City Fix | 7 Principles for Transit-Oriented Development