关于林区道路干支线经济分界点问题

根据林区道路网中的干线林道年运量大于支线林道年运量、干线林道的修建费比支线林道修建费高、干线林道运输费比支线林道运输费低的关系,用干线运输费的节省来补偿修建费的增加,推求干、支线林道的经济年运量。用经济年运量来划分道路等级,为道路规划、道路升级改造提供理论根据。通过分析可知,当回收期不变时,经济年运量随年利率增加而呈曲线上升;当年利率不变时,经济年运量随回收期的延长呈下降趋势。

ECONOMICAL DEMARCATION POINT ABOUT MAIN AND BRANCH LINE OF FOREST ROADS

The economical annual amounts of traffic of the main and branch line of forest roads were deduced by using the surplus of transportation expenses of the main line to make up with the increasing of construction expenses according to that the annual freight volume of the main line was higher than that of the branch line, and the construction expenses of the main line was higher than that of the branch line in forest road network. It provides a theoretical basis for road planning and improving to decide the road class by using the economical annual freight volume. It was found from analysis that the economical annual freight volume increased with the increasing of interest rate in curve when the recovery period was constant, but decreased with the prolonging of the recovery period of investment when the interest rate was constant.