Public facilities are public goods and services provided by the city government to the public for use or enjoyment,including transportation facilities,health facilities,cultural facilities and educational facilities.They are an indispensable part of the city.It provides an important guarantee for urban social and economic operation and residents'daily life.It is also the main embodiment of the city's competitive advantage different from rural areas and cities.However,due to the external effects of public facilities,residents always want to be adjacent to public facilities with positive externalities,while those public facilities with negative externalities are disgusted by nearby residents,and their planning,construction and layout will even cause resistance from nearby residents.Therefore,how to deal with the relationship between residents and public facilities has become an unavoidable sharp problem in the process of rapid urbanization and urban construction.
　　Negative externalities produce neighborhood avoidance effect.Generally speaking,urban public facilities have the characteristics of non competitiveness and non exclusivity of public goods,and have positive externalities for the majority of urban citizens.For example,in the free park in the city,nearby residents can easily carry out various cultural,sports and entertainment activities in the park,and residents of surrounding buildings can also overlook the beautiful scenery of the park;Urban rail transit makes residents'travel more efficient.