Discussion on the Sustainable Development Pattern of Road Network Structure of Cities with a Population of 1-2 Million in ChinaZhengmin Wen, Zhenqiang Li, Wenshuo Luo, Yuxin Fu, Juan Quan and Guohua ZhouE3S Web Conf., 237 (2021) 04018DOI: https://doi.org/10.1051/e3sconf/202123704018