交通发展滞后是制约山区发展的重要因素，定量评估山区交通通达情况对认知山区交通空间格局和进行山区交通开发具有重要的现实意义。在综述国内外交通地理文献的基础上，论文构建了以交通设施技术等级、距离交通枢纽的通行时间和交通线密度3个因子为核心的山区交通通达度测度模型，并引入交通摩擦系数来提高山区交通通达度测算的精度。利用该模型对四川省凉山州各县市的交通通达度进行了测算，结果表明凉山州交通通达情况总体较差，其中较差和极差的县市有9个，占全州国土面积的61.60%；交通通达度理想和良好的县市仅有3个，占全州国土面积的15.49%。凉山州的测算结果表明，山区交通通达度模型结构合理，测算精度高，在我国广大山区具有一定的应用价值。

The delayed development of transport is an important factor restricting the development of mountain areas.Quantitative assessment of transportation accessibility in mountainous areas is significant for understanding the transport spatial patterns and the development of transport in the future.This paper develops a transportation accessibility evaluation model for mountainous areas using three core factors.They are technical grades of transport facilities,time distance between the evaluation area and the central city and road density of the evaluation area.It also uses an index which is named traffic friction coefficient to improve the accuracy of transportation accessibility assessment in mountainous areas.Taking Liangshan region of Sichuan Province as an example,the transportation accessibility was computed by the model.The results show that the area with poor transportation accessibility and very poor transportation accessibility in Liangshan area occupies 61.60% of the total land area,and the area with better spatial accessibility and satisfactory transportation accessibility in Liangshan occupies only 15.49% of the total land area.The result also proves that the model developed in this paper has a high accurary and it is valuable for the mountainous areas of China.