基于路网的多车种空车调配优化方案研究

在分析现有典型空车调配模型特点的基础上,基于路网结构,核心考虑区间通过能力和不同车种间代用因素,将空车调配相关的走行费用、车种代用费用,以及库存费用共同纳入目标体系,构建了多车种空车调配改进模型,使空车调配更加符合铁路运输实际.通过算例模拟分析,验证了模型的可行性.     

在时间窗条件下应急物资运输路径优化问题研究

应急物资调运主要是应急车辆在最短的时间内把应急物资运送到需求点,其研究的核心是最短路径选择问题。通过对研究问题的描述,界定其中交通网络的道路和节点均带有禁止时间窗,模型目标是通过路径选择最小化调运时间,鉴于模型的组合属性,利用动态规划和标号法算法对设计问题求解,以实例计算说明模型算法的有效性。     

铁路应急物资储备点选址研究

通过概述国内外对于应急管理和应急系统选址问题的研究成果,根据铁路应急物资储备点选址问题的特点,以总货物周转量最小为目标,考虑以最少的储备点数量覆盖全部应急物资需求点,在铁路应急物资储备点的运输能力约束和应急物资需求点的需求约束条件下,建立铁路应急物资储备点选址模型,并采用LINGO软件对模型进行求解。算例分析表明,该模型适用于铁路应急物资储备点选址问题。     

基于车种代用的铁路网空重车调配优化研究

为促进空重车协同高效调配并提高货主满意度，在铁路空车调配经典模型的基础上，提出一种考虑车种代用的空重车协同调配模型，该模型考虑站点空车需求供给的随机分布、货车保有量、货运计划、空车车流直达等约束，以重车收入、车种代用费用、货运需求损失费用、空车调配费用的总收益最大化为目标，使得模型更加接近生产实际。针对构建的调配模型设计改进的蚁群算法，该算法采用信息素的局部更新以及全局更新来指导蚂蚁的状态转移。以某铁路网为例，研究结果中实现车种代用的敞车共有1 566车，在调配重车数中占比61.40%，可见合理的车种代用可以更大程度地满足运输需求；当敞车、平车单位空走费用不变，降低棚车单位空走费用时，对提高铁路运输收益更有效果。     

基于TOPSIS的铁路应急资源调度优化模型

突发事件下铁路应急资源的调度问题涉及多出救点、多资源的资源分配问题。针对由于救援紧迫性导致初期应急资源不足的情况,首先运用TOPSIS模型确定事故点的救援优先权;其次以资源调度总时间、总成本及惩罚成本最小作为目标函数,构建应急资源调度模型,并将事故点的优先权以时间系数和成本系数的形式加入到模型中,确保优先权较高的事故点优先获得应急资源;最后以自然灾害导致的区域铁路网内的多处事故为例,通过建模并运用LINGO11.0软件求解,验证模型的可行性和适用性。     

湖北省运管物流系统助力疫情防控与复工复产

自新冠肺炎疫情发生以来,湖北省运管物流系统积极做好客货运输应急运力准备,服从指挥和调度,安全有序完成了疫情应急物资、生活物资、重点生产物资、医护人员等运输保障以及五个应急物资调运站转运工作。后期,随着疫情形势向好,积极配合当地有关部门,对返岗人员采用"点对点、一站式"服务模式,精准输送务工人员返岗,助力企业复工复产。     

铁路煤炭调运问题的遗传算法

根据铁路运输中现有煤炭的运输状况，构造出煤炭调运时，煤种间不能相互代用和可以相互代用的数学模型，并基于遗传算法的C语言程序，对该模型进行了遗传算法设计，最后通过算例，验证了模型和算法的可行性。     

灾难救援应急物资配送问题的研究现状及发展方向

应急物资分配和车辆路径选择是灾难救援研究的2个核心问题。通过分类综述国内外学者关于应急物资分配和应急车辆路径研究的模型及结论,重点分析了模型的目标函数、约束条件、算法及优缺点。在灾难救援应急物资配送问题的研究分析中,提出考虑需求不确定性、建立更符合实际的模型、探索启发式算法、结合其他理论研究等研究方向。     

铁路应急物资运输网络中RAP问题的集成优化模型

通过概述国内外对铁路网络失效线路修复和应急物资配送问题的研究成果,针对RAP问题,将铁路运输网络中的修复失效线路与应急物资配送问题进行集成优化,以提高铁路应急物资的配送效率。首先对铁路应急物资运输网络进行脆弱性评估,其次以物资配送总效率最大和修复路径总延时最小为目标建立RAP的集成优化模型,然后利用0-1变量将模型转化为计算软件易于操作的规划模型,最后通过算例分析验证该模型的可行性和实用性。     

济南市连夜运送抗震救灾物资

5月19日晚22点12分，济南市交通局接到紧急通知，要求调运一批抗震救灾物资。济南市交通局立即启用应急运力，调用货车9辆，出动执法车2辆抢运了棉被、帐篷、食品等救灾物资。从接到紧急命令至圆满完成调运任务，济南市交通系统仅用不到3小时。图为运送救灾物资车队。     

A spatially distributed queuing model considering dispatching policies with server reservation

In this paper we propose a cutoff hypercube queuing model to analyze server-to-customer emergency services operating with server reservation. We are motivated by certain SAMU’s (Système d’Aide Médicale Urgente) that give assistance to different classes of emergency requests, including specialized transfer of patients, and use the reservation strategy to improve the probability that ambulances will be available to high priority calls. The aim is to show how this cutoff priority service discipline can be handled by the cutoff hypercube queuing model to evaluate relevant system performance measures, and the main impacts of this policy to the different classes of users.     

A statistical approach to small area synthetic population generation as a basis for carless evacuation planning

Natural or man-made hazards that require evacuation put already vulnerable populations in a more precarious situation. However, when plans and decisions about evacuation are made, the assumption of access to a private car is typically made and differences in income levels across a community is rarely accounted for. The result is that carless members of a community can find themselves stranded. Low income carless residents need alternative transportation means to reach shelters in case of an emergency. Thus, evacuation plans, decisions and models need necessary information that identifies and locates these populations. In this paper, data from the American Community Survey, US Census, Internal Revenue Services and the National Household Travel Survey are used to generate synthetic population for Anne Arundel County, Maryland using the copula concept. Geographic locations of low-income residents are identified within each subarea of the county (census tract) and their car ownership is estimated with a binomial logit model. The developed population synthesis method will allow officials to have a more accurate account of disadvantaged populations for emergency planning and identify locations of shelters, triage points as well as planning carless transportation services.     

基于随机机会约束的空车调整模型的研究

通过对比空车调整问题的确定性模型与实际问题之间的差异，提出一类随机机会约束模型来模拟实际空车调整问题。通过引入概率模拟实际问题中的不确定因素，将确定性模型转化为不确定性模型，以使模型能更准确的反映实际，并将经济学指标作为评价标准。通过遗传算法求解算例，表明模型和方法的有效性。     

Can high quality public transport support reduced car parking requirements for new residential apartments?

This paper explores the extent to which high quality public transport can support reduced car parking requirements for new residential apartment buildings. Using a case study of Melbourne, the demand for car parking at residential apartment buildings in proximity to high frequency public transport is assessed, while controlling for a range of socio-demographic, urban design and demand management variables. Key findings indicate that while lower demand for car parking is associated with proximity to high quality public transport, this association is not significant when controlling for other factors that influence car ownership. Public transport service supply within 800 m of residential apartment buildings was instead found to be significant, rather than simple distance to transit. Modelling results suggest an inelastic relationship whereby a 10% increase in public transport service supply is associated with a 0.9–1.2% reduction in car parking demand as measured by levels of car ownership. Notwithstanding broader criticisms of residential off-street parking minimums, the findings have important implications for the development of residential car parking policies, suggesting that city-wide car parking requirements should appropriately reflect the spatial distribution and quality of public transport services.     

Dynamic relief-demand management for emergency logistics operations under large-scale disasters

This paper presents a dynamic relief-demand management model for emergency logistics operations under imperfect information conditions in large-scale natural disasters. The proposed methodology consists of three steps: (1) data fusion to forecast relief demand in multiple areas, (2) fuzzy clustering to classify affected area into groups, and (3) multi-criteria decision making to rank the order of priority of groups. The results of tests accounting for different experimental scenarios indicate that the overall forecast errors are lower than 10% inferring the proposed method’s capability of dynamic relief-demand forecasting and allocation with imperfect information to facilitate emergency logistics operations.     

A model for time of day and mode choice using error components logit

The severity of road congestion not only depends on the relation between traffic volumes and network capacity, but also on the distribution of car traffic among different time periods during the day. A new error components logit model for the joint choice of time of day and mode is presented, estimated on stated preference data for car and train travellers in The Netherlands. The results indicate that time of day choice in The Netherlands is sensitive to changes in peak travel time and cost and that policies that increase these peak attributes will lead to peak spreading.     

A comparative evaluation of large-scale personal travel planning projects in England

Findings are presented from a study assessing the effectiveness of large-scale, residential-based personal travel planning (PTP) projects in eight areas in England. The project evaluation results show consistent reductions in car driver trips with an average reduction of 11%. The mode of travel that experiences the most substantial increase is walking with modest increases reported for cycling and public transport. Results have not been disaggregated according to the type of participation that individuals have had in projects; therefore, it is not possible to identify how project design influences outcomes. Despite the consistency of outcomes reported and many aspects of good practice in project evaluations, there are some concerns about evaluation methodology, notably that the estimation of outcomes might be systematically biased. The main concerns relate to independence of evaluators, sample sizes and survey response biases. A priority in future project evaluations is to use independent evaluators and to collect aggregate-level travel data with which to corroborate survey-based results and enable monitoring of outcomes over longer time-scales. Another priority is to increase the understanding of how design elements of PTP projects influence behavioural outcomes and to develop appropriate research methods to investigate this. Improved evaluations will better enable the value for money of PTP to be assessed relative to other investment options.     

Bus quality partnerships,modal shift and traffic decongestion

A more sustainable transport system requires effective alternatives to private cars. Despite more than 40 years of declining use, buses are still the main form of local public transport outside central London. Government policy focuses upon Bus Quality Partnerships—agreements between highway authorities and bus operators to give bus priority access and invest in better quality buses—to reverse this decline and also attract car drivers to change modes and ease urban traffic congestion.This paper assesses the potential for Quality Partnerships to provide a more attractive bus service with the ability to achieve modal shift using a Greater Manchester case study. Preliminary results are presented from a comparative study of two Quality Bus Corridors (QBCs), one arterial route into Manchester’s Central Business District and one transverse from Leigh to Bolton. The research uses bus user interview surveys and in-depth interviews, which focus upon non-bus users.Results of this research show that Bus Quality Partnerships when introduced as a stand-alone policy struggle to achieve significant modal shift and traffic decongestion. Most bus passengers and car users remain unaware of Bus Quality Partnerships.     

The impact of company-car taxation policy on travel behavior

This paper explores the impact of company car taxation on travel behavior. It focuses on a nationwide case study in Israel, which experienced a massive growth in the extent of company cars and which has implemented various policy changes in the taxation of company cars. A survey of 400 employees who have a company car and 230 employees who have only a privately owned car clearly points out the significant impact exerted by company cars on travel behavior, negatively affecting sustainable transportation development. The practice of and taxation policy in regard to the company car result in considerable extra mileage and encourage car usage by the employee's entire household. Changes in the taxation of a company car as well as in employer's policy toward company car usage may bring about a significant change in drivers' decisions regarding the willingness to have a company car and their travel behavior.     

Nonlinear effects of residential and workplace built environment on car dependence

The relationships between the built environment (BE) and car dependence have been thoroughly evaluated, with a primary focus on the residential BE; however, the effects of the BE at workplaces have remained largely unexplored. Little is known about the potential nonlinear effects of the BE at both locations. Using data from a household travel survey in Changchun, China, we aimed to reveal the nonlinear effects of the residential and workplace BE on car dependence by building a gradient boosting decision trees model. The results show that the BE at both locations has strong explanatory power for car ownership and car purchasing intention. With relative contributions values of 17.90% and 18.13%, respectively, the BE at workplaces contributes less to explaining the two dependent variables than the BE at residences. All BE attributes show nonlinear effects on car ownership, and car purchasing intention and the effects differ between residential and workplace locations.