与国省道相比,县乡公路的特点是:线短、面广、行车密度小、标准低、基础弱。但是,没有这些支线,国、省道干线就不能充分发挥作用,也就谈不上完善的公路交通网。目前,我国大部分县乡公路是等外路,这些等外公路技术状况差,汽车行驶质量低,社会经济效益也不等。因此,研究怎样很好地把这些等外路改造成全面符合标准的等级公路是很有必要的。笔者认为:现在许多县乡公路的设计质量亟待提高。其中较普遍地存在着的一个问题是,按某级公路技术标准改造或新建一条 Compared with the provincial highway, the characteristics of county and township roads are: short lines, wide area, driving density, low standards, weak foundation. However, without these branches, the national and provincial trunk lines can not fully play their role and there is no way to improve the road network. At present, most of the county roads in our country are off-road. The technical condition of these off-highway roads is poor. The quality of driving a car is low and the social and economic benefits are not the same. Therefore, it is necessary to study how to properly transform such off-road roads into fully-complied grade roads. The author thinks: Nowadays, the quality of design of many county and township roads needs to be improved urgently. One of the more common problem is that according to a certain level of highway technical standards to transform or create a new