Elasticity-based Model Applies in the Forecasting of Highway Induced Traffic

Induced traffic is a key part of travel demand analysis, which directly affects the urban transportation planning. The purpose of this paper is to address the question of how much new or improved road induces extra traffic. Based on the concept and mechanism of induced traffic, the factors that affect vehicle-miles of travel (VMT) are discussed. The elasticity-based model which is in general use is applied in the calculation of the provinces and cities of China. In accordance with the data collection (from 1990 to 2008), induced traffic is analyzed. And then the elastic coefficient of China and six districts (north China, east China, southwest China, south central China, northeast China, and northwest China) between VMT and lane-miles is estimated to be 0.16-0.51. Considering time delay, the elastic coefficient with one year lag and two year lag is about 0.22-0.54. Such data analysis not only confirms the existence of induced traffic, but also provides substantive recommendations to urban transportation planning.

摘要诱增交通量是交通需求预测中必不可少的一部分，它直接影响着城市交通规划. 为了探讨诱增交通量对于新建或改建道路影响情况，本文在明确了诱增交通量定义和产生机理的基础上，探讨影响我国出行距离的因素，应用国外普遍采用的弹性系数法对全国各省市（1990年–2008年）数据进行诱增交通量分析，得到了全国及六个分区（华北、华东、西南、中南、东北、西北）公路里程和出行距离之间的弹性系数0.16–0.51. 考虑时间作用，计算出延期一年、两年公路里程和出行距离之间的弹性系数0.22–0.54. 详尽的结果分析不仅证实了诱增交通量的存在，并为我国城市交通规划提供实质性建议.