地铁设计新规范之车辆基地设计体会

为了地铁车辆段工艺设计者更快地熟悉掌握应用地铁设计新规范,并创新车辆段工艺设计思路,通过对2013年版地铁设计新规范的学习,并结合笔者地铁车辆段工艺设计经历,对新旧地铁设计规范车辆基地篇章的主要区别及变化原因进行剖析与解读。归纳总结车辆段物业开发设计过程中的常见问题和应该把握的设计原则;车辆参数变化对车辆段工程设计的影响;车辆修程修制调整对车辆段规模的影响;运用整备设施设计参数的优化调整;检修设备设施及其他设施配置的明确调整等。     

地铁车辆段上盖开发相关问题及应对措施

对地铁车辆段上盖开发的内容、结构形式进行分类和分析,提出上盖开发的内容主要有公共建筑、住宅、公园及绿地等三类;上盖开发的结构形式有转换层大平台方式、核心筒落地方式、夹心落地等三方式。对由于上盖开发引起的行车安全隐患,盖下作业环境恶化,占地面积增加,建设费用增加,对消防交通及环境、振动和噪声、总图布置和检修工艺的不利影响等,提出应对措施。建议车辆段上盖开发应在较大的区域范围内结合城市规划进行综合分析研究,在城市中心地带,应做上盖开发;在城市的边缘地带,应在经济技术比较的基础上,确定是否进行上盖开发;在城市郊区不建议进行上盖开发。     

快速路可变限速与匝道控制协同优化策略

可变限速控制和匝道控制是快速路交通控制的主要手段,本文对两者的协同优化策略进行了研究.借助智能车路协同系统强大的信息感知能力,通过引入微观交通流信息,对经典METANET模型进行了改造,构建了可变限速控制影响下的微观METANET模型,实现了一种新的可变限速控制策略,同时,采用ALINEA算法,对入口匝道进行了优化控制,实现了两者的协同优化.最后,基于实际道路和交通流数据搭建了仿真平台,对微观METANET模型和协同优化策略的有效性进行了验证.仿真结果表明,微观METANET模型具有良好的交通流预测效果,协同优化策略能有效地改善快速路交通流状态.     

城市轨道交通车辆基地站场勘测内容和方法研究

车辆基地是城市轨道交通系统的重要组成部分,针对目前车辆基地勘测设计过程中普遍重设计轻勘测、缺乏系统的站场勘测内容与方法的现状,通过对行业、企业相关勘测规范的理解和归纳,结合自己勘测设计实践,系统论述车辆基地站场勘测内容和方法,主要包括车辆基地基线的测设和应用、地形测量、站场横断面测绘、专项调查与测绘等几方面,掌握车辆基地站场勘测内容和方法将为车辆基地设计与施工、节约用地、降低投资等方面发挥重要的作用。     

Accelerated vehicle retirement program: Estimating the optimal incentive payment in Israel

The paper analyzes two main aspects of the accelerated vehicle retirement program in Israel: the optimal incentive payment of private cars, and the feasibility of expanding the program to include light commercial vehicles. The benefits are the reduction of pollutant emissions and safety benefits, which were compared to the costs of the incentive payment. A differential payment scheme for private vehicles according to the vehicle’s age, is shown to have a higher net benefit than a uniform payment scheme. It is also found that the optimal payment is higher than the existing incentive payment. Additionally, it is found economically feasible to include light commercial vehicles in the program.     

浅谈高速公路桥头跳车的因素及预防措施

桥头跳车一直是高速公路投入使用后普遍存在的问题,本文通过查阅各种资料及本人施工经验,归纳总结了桥头跳车问题产生的原因,提出了桥头跳车问题的预防措施,以便为今后类似工程的施工提供参考。     

(Unintended) Transport impacts of an energy-environment policy: The case of CNG conversion of vehicles in Dhaka

Motor vehicles are one of the major sources of air pollution in Dhaka, the capital of Bangladesh. The government took various policies to convert the petroleum vehicles on road to run on compressed natural gas (CNG), which allows both air quality improvements and energy security benefits. One of the market friendly policies to encourage the fuel switch was to increase the price differential between CNG and petrol and diesel. This has allowed a wide-scale adoption of CNG as the fuel of choice. However, several years into the policy, there is now a widespread belief among the policymakers that the CNG conversion may have increased car ownership and car travel due to their lower running costs, resulting in more congestion and a reversal of the strategy is on the cards. It is therefore important to test the hypothesis whether CNG conversion had genuinely increased car ownership and car travel in Dhaka city. This paper presents the results of a questionnaire survey and an econometric intervention analysis to understand the impact of CNG conversion on car ownership and car travel in Dhaka. Attention is also given to disentangle the self-selection and price-induced travel effects of CNG conversion. Results show that ownership did not increase, but travel of on-road vehicles increased due to the CNG policy. However, additional congestion costs are still around one half of the health benefits brought about by the policy.     

Order-first split-second methods for vehicle routing problems: A review

Cluster-first route-second methods like the sweep heuristic (Gillett and Miller, 1974) are well known in vehicle routing. They determine clusters of customers compatible with vehicle capacity and solve a traveling salesman problem for each cluster. The opposite approach, called route-first cluster-second, builds a giant tour covering all customers and splits it into feasible trips. Cited as a curiosity for a long time but lacking numerical evaluation, this technique has nevertheless led to successful metaheuristics for various vehicle routing problems in the last decade. As many implementations consider an ordering of customers instead of building a giant tour, we propose in this paper the more general name of ordering-first split-second methods. This article shows how this approach can be declined for different vehicle routing problems and reviews the associated literature, with more than 70 references.     

Evolution of the household vehicle fleet: Anticipating fleet composition, PHEV adoption and GHG emissions in Austin, Texas

In today’s world of volatile fuel prices and climate concerns, there is little study on the relationship between vehicle ownership patterns and attitudes toward vehicle cost (including fuel prices and feebates) and vehicle technologies. This work provides new data on ownership decisions and owner preferences under various scenarios, coupled with calibrated models to microsimulate Austin’s personal-fleet evolution.Opinion survey results suggest that most Austinites (63%, population-corrected share) support a feebate policy to favor more fuel efficient vehicles. Top purchase criteria are price, type/class, and fuel economy. Most (56%) respondents also indicated that they would consider purchasing a Plug-in Hybrid Electric Vehicle (PHEV) if it were to cost $6000 more than its conventional, gasoline-powered counterpart. And many respond strongly to signals on the external (health and climate) costs of a vehicle’s emissions, more strongly than they respond to information on fuel cost savings.Twenty five-year simulations of Austin’s household vehicle fleet suggest that, under all scenarios modeled, Austin’s vehicle usage levels (measured in total vehicle miles traveled or VMT) are predicted to increase overall, along with average vehicle ownership levels (both per household and per capita). Under a feebate, HEVs, PHEVs and Smart Cars are estimated to represent 25% of the fleet’s VMT by simulation year 25; this scenario is predicted to raise total regional VMT slightly (just 2.32%, by simulation year 25), relative to the trend scenario, while reducing CO₂ emissions only slightly (by 5.62%, relative to trend). Doubling the trend-case gas price to $5/gallon is simulated to reduce the year-25 vehicle use levels by 24% and CO₂ emissions by 30% (relative to trend).Two- and three-vehicle households are simulated to be the highest adopters of HEVs and PHEVs across all scenarios. The combined share of vans, pickup trucks, sport utility vehicles (SUVs), and cross-over utility vehicles (CUVs) is lowest under the feebate scenario, at 35% (versus 47% in Austin’s current household fleet). Feebate-policy receipts are forecasted to exceed rebates in each simulation year.In the longer term, gas price dynamics, tax incentives, feebates and purchase prices along with new technologies, government-industry partnerships, and more accurate information on range and recharging times (which increase customer confidence in EV technologies) should have added effects on energy dependence and greenhouse gas emissions.     

Vehicle restrictions and CO2 emissions in Beijing – A simple projection using available data

The Beijing Government launched a new policy on restricting vehicle ownership in late 2010 to regulate the faster motorization and the excessive vehicular carbon dioxide (CO₂) emissions. In this paper, we first analyzed this policy and its effect on private passenger vehicle population. The private passenger vehicle population in Beijing from 2011 to 2020 was predicted under three different scenarios: no constraint (NC), current constraint (CC) and tighter constraint (TC). Then the assessment of vehicular emissions reduction benefits was made on the basis of private passenger vehicle population, vehicle kilometers traveled and CO₂ emission factors. It was projected that the CO₂ emissions in 2020 will reach 23.90, 15.55 and 13.23 million tons under NC, CC and TC respectively. The policy is very effective in controlling the faster motorization and reducing CO₂ emissions.