由于张九龄(678—740年,广东曲江人)遇事直言谏诤,不免与朝中官宦时有冲突,因而往往受人冷落。他深感平生抱负不能见伸,心里非常失望,便告病辞归,退隐山林。他在家居期间,想起故乡粤北乡亲的多年愿望——打通大瘐蛉使能联结南北的交通时,便于唐开元四年(716)上书玄宗,请开大瘦岭道,为发展岭南经济开辟一条交通运输通道。 Due to Zhang Jiu-ling (678-740, Qujiang, Guangdong), his case of misconduct can not help but be in conflict with the officialdom of the DPRK and is often left out by the people. He was deeply satisfied with his vision of life can not see stretch, my heart was very disappointed, he resigned, leave the mountains. During his stay in his hometown, he remembered the long-standing desire of his hometown, the villagers of Yuebei, to open up the grand 瘐 蛉 to enable the traffic linking north and south. This was a good time for Tang Kaiyuan to write a letter Xuanzong in the fourth year (716) A transport corridor.