以北京市为例,从系统动力学角度分析城市私家车拥有量发展问题。剖析各要素间相互关系建立流图,通过VENSIM平台构建SD模型,在历史统计数据的基础上结合北京市"公交优先"的政策背景模拟私家车总量发展趋势,并根据2008奥运北京机动车实行"单双号限行"的措施,研究了长期实行该制度将对城市机动车和私家车拥有量未来变化造成的影响,为合理控制私家车总量给予了一定的政策建议。模型仿真与分析结果表明,在现阶段北京市私家车数量仍处于S形曲线的快速增长期,并未达到规模峰值,需要对其发展趋势进行关注和必要控制。而相对于车辆限行政策,大力发展公交事业可有效限制私家车总量,且不会随时间产生负面影响,是更为科学合理的调控措施。
Taken Beijing as a case of study, the amount development of private cars was analyzed by using system dynamics. With the flow chart illustrating the interrelationship of relevant traffic elements and statistical data in the past years in Beijing, a SD 'model was established by VENSIM to simulate the developing trend of private cars' amount on the background of "transit priority" policy. In view of "odd-and-even license plate rule" during the Beijing 2008 Olympic Games, the impact of this rule on quantities of urban vehicles and private cars in the future was studied under the assumption of this rule implemented for long period and then some recommendations for reasonable control were put forward. The results of model simulation and analysis show that ( 1 ) since the number of private cars in Beijing is still in rapid growth period of S growth curve and it has not reached the peak yet, it is necessary to give certain concern and control on its development trend at current stage; (2) compared with the vehicle restriction policy, "transit priority" which limits the number of private cars effectively without negative effect over time is a more reasonable and scientific control measure.