 At the time Nanjing, Wuhan, Chongqing, Dalian and Shenzhen had advanced proposals waiting to be approved.Wuhan, Chongqing, Dalian managed to circumvent the moratorium on subway construction by constructing and opening lower cost elevated lines, light metros, and monorails in the early 2000s.Rapid urbanization of China lead to severe congestion and pollution in urban areas leading to the suspension being lifted.