The expressway connected Guigang City and Long'an, county of Nanning City, in south China's Guangxi Zhuang Autonomous Region opened to traffic on Wednesday, aiming to boost the connectivity in Greater Bay Area, which comprises of Hong Kong, Macao and nine cities in Guangdong Province. A pair of non-stop bullet trains between Nanning and Hong Kong Special Administrative Region was also launched, connecting the two within four hours.