独木桥

single-log bridge / (fig.) difficult path

alone / independent / single / sole / only

(bound form) tree / (bound form) wood / unresponsive; numb; wooden

bridge / CL:座[zuo4]

lit. you hit the high road, I'll cross the log bridge (idiom) / fig. you go your way, I'll go mine / you do it your way, I'll do it mine