Second-level national highways stretch 958 km (595 mi), third-level highways, 7,571 km (4,704 mi) and fourth-level highways, 52,248 km (32,465 mi). The province has formed a network of communication lines radiating from Kunming to Sichuan and Guizhou provinces and Guangxi and Tibet autonomous regions, and further on to Burma, Laos, Vietnam and Thailand.