Kunming has built up its second ring road, forming a communication network with three west-eastern roads, four north-southern roads, five outlets and 19 overpasses.
Storm water samples collected from an urban road in Xi′an City show that the urban road surface runoff has much greater pollution intensity of SS and COD and possess less biodegradability.
Traditional downtown Xi'an refers to the area encircled by the city wall, this has now been expanded to encompass the area within the second ring road (Er' huan Lu).
Lijiatuo area is located between Jiefang Road and Fuqing Road, covering the area of First Ring Road and Second Ring Road. It is the largest residential district in the north of Chengdu.