基于风险分布公平性的公路危险品运输全局路径优化研究

Hazardous materials transportation global route optimization considering the equitable distribution of risks on road sections

首先,通过计算危险品运输事故各种后果产生的概率及其相应经济损失价值,建立了基于各种损失价值的定量运输风险评价模型;其次,通过对各路段施加统一的危险品总容量限制以确保风险分布的公平性,建立了加权最小运输成本和最小运输风险的双目标全局路径优化模型;再次,将基尼系数和方差系数作为基于路段的风险分布公平性的衡量指标以进行路径方案比选,并进行了适用性分析。算例分析表明:一方面,通过有规律地改变2个优化目标的权重,可以得到路径优化模型的所有帕累托最优解的集合;另一方面,通过恰当设定路段危险品总容量限制,以及对2个优化目标选择合适的权重值并进行全局路径优化,可以使所得到的最终路径方案的社会总成本大幅降低,并在一定程度上保证路段风险分布的公平性。

The paper is aimed to present our study on the hazardous materials transportation global route optimization considering the equitable distribution of risks on road sections, For this goal, we have done the following studies： First of all, based on the calculation of the costs and the accident-incidence probability of various possible losses, such as the environmental damage, the property damage, fatalities, traffic incident delay and evacuation in hazardous materials road transportation accidents, we have established a quantitative transportation risk evaluation model, which can be used to represent all the relevant consequences in terms of monetary currency; Secondly, we have also built a bi-objective global route optimization model with the weighted combination of the minimum transportation cost and minimum transportation risk by imposing uniform capacity restriction on the dangerous goods freight volumes of each road section in hoping to improve both the safety and the economy of the route, while ensuring the equitable distribution of the risks involvd; Thirdly, we have chosen the Gini coefficient and the coefficient of variation as the measures of the risk equity based on the road sections to select the best or desirable route from the solutions to the above models while discussing the suitability of the two indicators; And, last but not the least, the case study we have done shows that, on the one hand, it is necessary to change regularly the weight between the two optimization objectives with the purpose to find the Pareto optimal solution sets by choosing the above optimized models, on the other hand, it is highly probable to reduce the total social cost of the ultimate route scheme greatly and improve the equity of the risk distribution to some extent by setting an appropriate capacity limit of the dangerous goods freight quantities for each road section and by choosing a proper weighed value between the two goals of the global route optimized model.