In 1993, American architect Peter Calthorpe first introduced the concept of Transit Oriented Development (TOD) in his book The Next American Metropolis: Ecology, Community, and the American Dream. This is a public transport-oriented urban planning approach to resolve the car-oriented urban problem at the time, with the priority is given to public transport. As a city planning principle, TOD helps to ensure that cities can create a vibrant, people-oriented community by maximizing access to public transport and thereby to economic activities. Therefore, after decades of academic promotion, the TOD principle has finally been widely accepted by different countries around the world.
The TOD concept has since been widely recognized and applied in densely populated cities in the United States, Western Europe, and Asia. With China's rapid urbanization based on its "land-economy", many Chinese cities have begun to adopt TOD as the standard. Along with the rapid construction boom of the subway in recent years, the TOD model has become popular in major cities in China. However, looking at TOD projects in China, most of them have deviated from the original intention of the TOD model. A large part of the focus has been placed on the construction of the public transportation system, with multiple seamless public transportation routes erected as the core. The construction of the walking and bicycle systems are either abandoned or not brought up. For instance, it was mentioned in one city planning program that with a subway station acting as a platform, a comprehensive transportation hub that radiates across the country will be built. It will then be transformed into a superstation hub with the integration of a planned subway line 3, bus station, as well as taxi pick-up and drop-off area. Such an urban development philosophy cannot realistically be regarded as an urban development concept that is truly people-oriented and that aims to bring about urban prosperity.
According to China's 2019 blueprint for urban rail TOD, increasingly more cities have introduced their own TOD policies in recent years, though they mainly come from first and second-tier cities. In particular, more cities have also begun to pay attention to the development of rail-based TOD. The blueprint shows that in recent years, the mileage of urban rail transit in China has basically maintained an average annual increase of more than 15%. In 2018, the total mileage of national rail transit reached 5,671 kilometers, an increase of 16.4% over the previous year. The number of cities that have opened new rail transit infrastructure has also grown steadily, reaching 32 in 2018, representing an increase of four over the previous year. Statistics also show that the overall urban rail transit utilization rate reached 47% in 2018. From 2018 to June 20, 2019, the national urban rail transit plan was approved for a total of 10 cities, involving 55 lines, with a total investment amount of RMB 1,054.505 billion. If the development of sites along the transit routes are taken into consideration, the TOD project will be a trillion-scale market, in terms of RMB. The market expects that in the next three to five years, many cities will be networked, and the rail transit network will reconstruct the existing urban spatial pattern.
However, it is far from sufficient for urban development to have only the TOD principle to guide it. Nor can the TOD principle be narrowed down to be regarded as the theoretical basis for the development of rail transit. ANBOUND's chief researcher Chan Kung, believes that the TOD principle is a balanced trend for urban development, freeing the city out of the private vehicle transportation system and rethinking the needs of people in the city. However, from the perspective of people-orientation, such balance and reconstruction efforts are still insufficient. Although the TOD system emphasizes public transportation and not just cars, the actual development of cities around the world has time and again overemphasized automobiles and transportation hubs while ignoring pedestrians. The city's communication system is therefore hierarchical in nature, and the TOD cannot break through the original transportation system hierarchy of the city. It cannot reconstruct the road rights in the land-economic sense, nor can it solve structural problems in the urban economy to ensure the urban economy and the street vitality. From this, it can be argued that the TOD principle is in fact an outdated principle.
In the second half of China's urbanization process, another principle -- POD(pedestrian-oriented development)principle should be adopted to promote urban development which focuses more on people, working to awaken urban vitality and enhance urban prosperity. Chan Kung systematically summarized and concluded that the concept of POD should be defined as a pedestrian-oriented urban spatial strategy and development strategy. Urban development under the POD concept aims to build and create urban public spaces that are highly friendly to pedestrians. With POD, creating a high quality of urban environment and urban service will be the main goal, as this affects urban planning and spatial relations, livable cities and communities, urban transformation and revision, urban industry, urban vitality, urban consumption, architectural design, urban modernity, urban environment, urban culture and many other fields.
Unlike TOD, which emphasizes traffic-oriented planning, POD emphasizes the priority development of the pedestrian system. The most elementary forms of vitality present in a city comes from its people. A city is a system of people and it is a living organization, not a system of transportation. In the latter case, people are relegated to being merely adjuncts to the transportation system. The POD principle stresses that people in the city are the first priority in the development of various levels of the pedestrian system. The public and private transport systems are just linkage systems of blocks. It must be established on top of a well-established and effective pedestrian system or should be thought about as an extension of the pedestrian system. Therefore, the POD principle actually subverts and innovates the original urban design and development principles, but such design and development principles are effective and can solve many practical problems in the cities.
In particular, as China moves from a purely production-oriented society to a society with balanced production and consumption levels, China's urban economic development will rely more heavily on consumption and service industries. In other words, consumption and service industries will become important driving forces for the economic development of many cities in China. Currently, some major cities in China (such as Beijing and Chengdu) that understands this trend have taken the development of "consumption center" as one of their important development goals. For these cities, the construction and transformation of cities based on the POD principles has a significant relationship with the development of "consumption center". Only by putting people first, paying attention to the rights of pedestrians, and taking a "consumption center" as the goal to build and transform urban space, can the sustained prosperity and the proper balance of the urban economy be truly brought to life. In addition, the POD principle is not necessarily contradictory to the TOD principle. The former is an important supplement to the latter. However, if a city only attaches importance to the TOD principle and does not attach importance to the POD principle, there will be a dislocation between its urban development stage and development principles.
Final analysis conclusion:
In the future, the development of Chinese cities will place more emphasis on the pedestrian-oriented aspects, requiring POD principles to promote the sustainable prosperity of cities.
