Dealing with the efficient allocation of scarce resources at congested airports

The existing slot allocation mechanism, based on the International Air Transport Association (IATA) system and its complementary version of the European Union (EU) regulation, produces rather poor capacity allocation outcomes for congested EU airports since it fails to properly match slots requested with slots allocated to airlines. Inefficiencies during the initial allocation are mainly due to the problem complexity in conjunction to limited decision support available to slot coordinators. On the other hand, substantial inefficiencies give rise to severe slot misuse and unreasonably low utilisation of airport resources running already into scarcity. The objective of this paper is to develop an optimisation-based model implementing the existing EU/IATA rules, operational constraints, and coordination procedures with the ultimate objective to better accommodate airlines’ preferences at coordinated airports through the minimisation of the difference between the requested and the allocated slot times to airlines. The results of the model are assessed and compared vis-à-vis the allocation outcome produced according to current slot coordination practice in three regional Greek airports. The proposed model produces very promising results and demonstrates that there is large room for improvement of the efficiency of the current allocation outcome in a range between 14% and 95%. The discussion of the model results is complemented by a sensitivity analysis highlighting the importance of declared capacity and the magnitude of its influence on slot allocation efficiency.     

Assessment of product debundling trends in the US airline industry: Customer service and public policy implications

This paper reviews product debundling trends that have occurred in the US airline industry. Multiple sources of ancillary fees related to ticketing refunds and exchanges, checked baggage, on-board pets, preferred and/or advanced seating assignments, frequent flyer ticket redemptions, and day of departure standby policies are reviewed. Despite the fact that both low cost and network carriers stress the importance of future ancillary fees in their investor reports, our assessment suggests that these fees will be more broadly adopted by low cost carriers. We anticipate that many network carriers will eliminate ancillary fees, particularly as they begin to recognize how these fees can impact other system performance objectives such as minimizing the number of misconnecting passengers. We estimate that the debundling phenomenon has diluted revenues to the US Airport and Airways Trust Fund by at least 5%.     

时速160 km城市轨道交通内置式泵房板式道床动力特性分析

北京轨道交通新机场线在部分区间隧道的最低点设置了内置式泵房板式道床。为了保证时速160 km市域列车在动荷载作用下轨道结构的安全性和可靠性,建立了车辆-轨道-隧道三维耦合动力分析模型,计算分析100~220 km/h共7种行车速度下内置式泵房板式道床的动力特性。提取道床振动评价指标(垂向位移、垂向加速度)、道床强度评价指标(纵横向拉应力)、行车平稳性评价指标(车体垂向、横向加速度)和行车安全性评价指标(轮轨垂向力、轮轨横向力、脱轨系数、轮重减载率)与规范允许值进行对比。计算结果表明,各动力学评价指标均随行车速度的增大而增加,各动力学评价指标均在规范允许值之内,并且有较大的安全余量。     

Investigation of environmental justice analysis in airport planning practice from 2000 to 2010

Municipal airport owners and the Federal Aviation Administration (FAA) regularly evaluate capacity and demand to decide if and when airports need more infrastructure. New infrastructure can alter the profile of noise, emissions, and land use, which may affect the quality of life for airport-adjacent communities. When the FAA and airport owners initiate infrastructure expansion, they must conduct environmental justice analysis to measure the distribution of negative externalities on nearby communities. This research investigates the environmental justice methodologies and narratives reported in planning documents for nineteen airport capacity expansions planned or deployed from 2000 to 2010 in the United States. The mixed-methods approach analyzes airport operations data, spatial demographic data, and planning artifacts to determine whether the environmental justice analyses were robust. This research proposes alternative metrics, the ‘Risk of disproportionate impact’ and ‘Capacity strain’, to further contextualize the presence of protected population groups alongside capacity needs. The main finding of the study is that the planning documents did not consistently detect environmental justice impacts, nor did they consistently confer importance to those impacts when high proportions of protected populations were detected. As a result, the social costs of collective airport expansion are unclear and likely underestimated. This study identifies two limitations that undermined the environmental justice analysis throughout the airport sample: (1) inconsistent methodological choices impeded the detection of impacts and, (2) narrative interpretations tended to ‘null’ the finding even when impacts were detected.     

时速160 km城市轨道交通双块式轨枕设计

为研究城市轨道交通有挡肩双块轨道结构的稳定性,依托国内首条时速160 km城市轨道交通线路-北京轨道交通新机场线,对有挡肩双块式轨枕进行尺寸设计及配筋设计:(1)结合线路特点,对有挡肩双块式轨枕承轨台抗压能力及挡肩抗剪能力进行检算;(2)为计算桁架钢筋受力情况,通过有限元模型计算起吊、堆载、施工上人3种工况下双块式轨枕的受力情况。计算结果表明,起吊及施工上人荷载对双块式轨枕的受力性能影响不大;堆载对其受力性能有较大的影响,双块式轨枕的堆放层数不应大于6层。     

北京新机场线高架地段双块式无砟轨道结构设计

北京新机场线是我国首条最高速度达160 km/h的地铁线,轨道结构采用双块式无砟轨道,高架地段首次采用取消底座结构设计,为了保证轨道结构的安全可靠,有必要对无砟轨道道床结构进行结构选型及配筋设计。通过建立高架地段无砟轨道结构的有限元模型,对道床板板长、板宽、板厚进行了选型分析。针对无砟轨道无底座设计方案,考虑了列车荷载、温度梯度、桥梁挠曲3种主要荷载类型,提出了荷载组合方案,研究其关键控制因素,对道床板进行了配筋设计及检算。通过参数比选,完成了道床板的尺寸参数选择;在3种荷载类型中,温度梯度在道床板中引起的弯矩值最大,在设计荷载中占据主导因素,合理减小道床截面高度可有效降低温度梯度作用;道床板配筋应以控制裂缝为原则进行设计。     

Measuring the equity effects of a carbon charge on car commuters: A case study of Manchester Airport

This papers attempts to quantify the equity effect of a hypothesized economic instrument, a carbon charge on car commuters, for reducing carbon dioxide emissions produced by commuters on airport surface access. Manchester Airport is taken as a case study using staff Survey data from 2008 and 2010. Consumer welfare change is analysed for measuring the equity effects of carbon charge by user group, which considers the changes of travel mode choice, the carbon dioxide emissions reduction, the revenue from a carbon charge and how it is distributed. First, the individual carbon footprint in terms of gram passenger kilometre, and the damage cost of carbon by commuters on airport surface access are estimated. Next, the impact of carbon charge on travel behaviour is investigated by the nested logit model. Finally, the net effect of carbon charges is assessed by travel mode user, gender, job type, and age group. The results show some impacts of the carbon charge on car users and carbon reduction, and the positive effects on lower income group and less carbon commuters. The quantified results provide the evidences for the mitigation policies to combine monetary incentives with disincentives for travel behaviour change, and demonstrate the different equity effects among commuter groups.     

Evaluating the operational performance of airside and landside at Chinese airports with novel inputs

ABSTRACT

This paper evaluates the operational performance of airside and landside at Chinese airports with two novel inputs. Furthermore, the airport landside operation is decomposed into passenger-terminal operations and cargo-warehouse operations. One novel input is the capability of the runway system which is introduced into airside performance evaluation. The other novel input is cargo warehousing which is introduced into landside performance evaluation. To address multiple optimal solutions when estimating Returns to Scale in Data Envelopment Analysis, we adopted the Zhu and Shen method. This empirical study shows that neither the number of runways nor total runway length is a genuine index of runway system capability in the evaluation of airside performance. Only four airports achieved full efficiency in all eight measures while eight airports did not achieve any full efficiency. In addition, one airport did not perform well in the benchmark analysis.     

民用机场建设与城市发展适应性评价研究

针对部分城市盲目新建或扩建机场问题,本文提出机场建设应与城场和城市发展的因果关系分析,建立了一套机场建设规模和选址布局与城市并用模糊综合评价法对机场适应性进行分析评价,最后结合成都市双流机场证明了方法的有效性。市发展相适应的概念。通过机发展适应性评价的指标体系,进行了实例分析,分析结果