Huadu District, Guangdong Province has a very important geographical position, known as &”;the barrier of the provincial capital and the throat of South and North Guangdong&”;. It is not only the traffic intersection of the Pearl River Delta, but also the bridge and hub connecting the Pearl River Delta with the mainland. It has a developed three-dimensional traffic network of water, land and air, and is a high-speed and wide-ranging three national highways and airports. …