西部地区山多坡陡,地质病害多发,低等级公路占比较大。道路通行能力、安全保障能力及抗灾能力都比较弱。“十三五”时期国家将加快完善西部地区交通条件。根据需求的不同,西部地区低等级公路改建项目大体上可分为完善改建和升级改建两类,设计中应有针对性的制定改建原则和目标,选择经济合理的公路改建方案。 Mountainous slopes in the western region are steep with many geological disasters and low-grade highways occupy a large proportion. Road capacity, safety and resilience are relatively weak. “13th Five-Year ” period, the state will speed up the improvement of traffic conditions in the western region. According to different needs, the reconstruction of low-grade highways in the western region can be divided into two categories, that is, rebuilding and upgrading. In the design, the principles and objectives of rebuilding should be formulated in a targeted way and the reasonable road reconstruction plan should be selected.