太行道 / Taihang Road
太行道 / Taihang Road enters the wiki through 《资治通鉴·周纪》92丨历史上第一位著名舔狗是谁？（1） as the route 白起 attacks after taking 韩国南阳. In the episode’s reading, controlling or cutting this road severs the connection between 上党 and Han’s capital region around Xinzheng.
The road matters because the campaign is about movement and communication as much as land. Once the Taihang route is cut, Shangdang becomes difficult for 韩国 to support or command, and a local decision not to surrender to 秦国 can become the trigger for a larger Qin-Zhao conflict.