The ring of the Hangzhou Bay Ring Expressway is entirely in Zhejiang Province. It begins at its southern end in Gaoqiao, Yinzhou District, Ningbo, at an interchange with the G15 Shenyang–Haikou Expressway and the G1504 Ningbo Ring Expressway. Clockwise, it follows the southern shore of Hangzhou Bay to Hangzhou, where it turns north and becomes concurrent with G60 Shanghai–Kunming Expressway and G2504 Hangzhou Ring Expressway. The G2504 Hangzhou Ring Expressway eventually splits off to the west at an interchange in Jianggan District, and the Hangzhou Bay Ring Expressway turns to the east as it splits with the G60 Shanghai–Kunming Expressway. The expressway continues eastward, following the north shore of Hangzhou Bay until it reaches an interchange with the S11 Zhapu–Jiaxing–Suzhou Expressway and the G15 Shenyang–Haikou Expressway in Jiaxing. At this interchange, the extra, non-orbital section of expressway to Shanghai branches off to the north while the orbital continues to the south and crosses the bay using the Hangzhou Bay Bridge. This section, including the Hangzhou Bay Bridge, is concurrent with the G15 Shenyang–Haikou Expressway. After the bridge, the expressway continues south past Cixi City to an interchange with G9211 Ningbo–Zhoushan Expressway and G1504 Ningbo Ring Expressway. It continues south in a concurrency with G15 Shenyang-Haikou Expressway and G1504 Ningbo Ring Expressway for a short section in Yinzhou District before returning to its southern terminus.
