Effect of climate change on asphalt binder selection for road construction in Italy

This work explores the influence of climate changes on the proper selection of asphalt binder for pavement construction purposes, according to the Performance Grade (PG) defined in the SUPERPAVE specifications. Based on temperature data at national level, it is possible to obtain thematic maps for the whole Italian territory, which is extremely useful for technicians and pavement engineers for selection of asphalt binder for road construction purposes. Furthermore, the statistical significant temperature trends’ knowledge enables deriving thematic maps which allows to include the effects of climate change in the asphalt binder design. It is argued that, due to climate change, the binders to be selected may be different from those commonly selected at the design stage of the infrastructure, since likely higher temperature determine more demanding constraints. The comparison among the PG grades necessary for covering the needs for construction in the different regions of Italy also call for highly performing binders, such as those obtained via specific modification with polymers. This will also imply the need for even more performing materials, in terms of mechanical properties and durability, to be used for modification of neat asphalt as well as the need for defining new specification and testing methods, specifically valid for these modified materials.     

Transport discussion amidst climate challenges: Analysing student,media, and expert framings through the environmental protection process model

The article examines media representations and views of experts and high school students on the future of transport with a particular focus on its implications for emissions of greenhouse gases. Focusing on Finland, it explores which key features and boundary conditions related to the climate policies of transport are framed as important or negligible. The analysis was based on the comprehensive environmental protection process model. Results show that the need for radical change was recognised both by students and experts but at the same time, rather cynical views regarding the possibilities to achieve these changes were presented by the media, experts, and students. Long-term impacts and visions were underrepresented in discussions, with the focus being mainly on short-term concerns and incremental changes.     

Stimulating Vertical Integration in Coastal Management in a Federated Nation: The Case of Australian Coastal Policy Reform

Four decades ago Australia was credited as being an early leader in implementing integrated coastal management (ICM). Nevertheless, as a federation of states and territories Australia has since struggled to fully implement vertical integration of its coastal governance arrangements. In particular the federal government has historically possessed only a minor role in coastal management despite the recommendations of several major inquires suggesting that this role needed to be enhanced. This article examines a series of circumstances and events over the past two years in Australia that has created the opportunity for the federal government to adopt a more significant and prominent role in coastal management and hence to substantially complete the vertical integration of ICM in Australia. These stimuli for coastal policy reform could also play a role in enhancing ICM in other federated nations.     

Implications of climate change for thermal discomfort on underground railways

Hot weather events, ventilation assets, changing passenger demand and service expectations have all caused increased attention on thermal comfort on London’s Tube. This study provides estimates of the future number of days when passengers travelling on sections of the Tube could be subjected to thermal discomfort under future scenarios of climate change, and the potential number of passengers dissatisfied. A risk based methodology is presented, integrating a spatial weather generator modified for urban areas and a thermal comfort model. The study provides an initial assessment of adaptation options by considering the implications of lowering train temperatures by 2 °C and 4 °C to represent saloon cooling. Median results under a 2050 high scenario indicate that all Tube lines assessed could experience near-complete passenger dissatisfaction with the thermal environment in trains in the unlikely event that nothing else were to change. Adaptation aimed at lowering train temperatures has the potential to provide tangible improvements in thermal comfort. However, this was not projected to be sufficient to maintain comfortable thermal conditions for many of the lines in the 2050s under high emission scenarios, requiring a combination of other infrastructure cooling measures to be implemented in parallel.     

Evaluating choice of traction option for a sustainable Indian Railways

The transport sector is a major contributor of carbon emissions in India. As railways are the most environment-friendly mode of transport we look at the spearheading role of Indian Railway (IR) in bringing about the modal shift from road and airways to rail with a holistic perspective considering India’s development stage and resource situation. India being an emerging economy, faces many other social and developmental challenges, which have to be incorporated in assessing the viability of the solutions. In order to assess the total impact of the transportation sector a ‘wells to wheels’ approach needs to be adopted to quantify the emissions from the production to distribution and final usages alongside its impact to the competing societal goals utilizing the same resources. This study focuses on evaluating IR’s critical policy decision towards providing efficient transport i.e. the choice of traction. It is inferred that until such time the fuel mix of power production in India remains the same, i.e. coal dominated and there is a shortage of electricity in the country, the accumulated carbon footprints of running electric locos will be higher. There should be a judicious mix of both the tractions to achieve a balance in environmental efficacy, sustainability and equity.     

Economic analyses of sea-level rise adaptation strategies in transportation considering spatial autocorrelation

This paper reports the impacts of economic analysis results on sea-level rise adaptation decision making with different economic analysis methods. The methodology was applied to Hillsborough County, Florida. A general conclusion is that partial shoreline protection should be implemented to reduce the potential impacts of sea-level rise on important land use, then transportation infrastructure is preferred to be protected or accommodated, and finally managed relocation should be adopted. More specifically, the results show that the best adaptation strategy is shoreline protection plus transportation infrastructure accommodation; the length of shoreline protection plays an important role in the economic analysis results, and shoreline protection and accommodation adaptation strategies for all areas are not recommended because of either high costs or low benefits; the value of travel time saving and spatial autocorrelation play important roles in the economic analysis results of accommodation strategy, which highlights the importance of including indirect economic factors and spatial autocorrelation impacts when making sea-level rise adaptation decisions.     

Q235钢焊接熔合区在混合菌共同作用下的腐蚀行为

通过观察腐蚀形貌,测量极化曲线和阻抗谱,研究了Q235钢熔合区在SRB和V.natriegens共同作用下的腐蚀行为。研究表明,熔合区的腐蚀程度,单一菌溶液中,SRB大于V.natriegens,混合菌溶液大于单一菌;混合菌溶液中SRB和V.natriegens表现出协同作用,加速试样的腐蚀;试样的耐腐蚀性能,熔合区小于焊缝区小于母材区。     

Older People's Mobility: Segments,Factors, Trends

Abstract

The expanding older population is increasingly diverse with regard to, for example, age, income, location, and health. Within transport research, this diversity has recently been addressed in studies that segment the older population into homogeneous groups based on combinations of various demographic, health-related, or transport-related factors. This paper reviews these studies and compares the segments of older people that different studies have identified. First, as a result of a systematic comparison, we identified four generic segments: (1) an active car-oriented segment; (2) a car-dependent segment, restricted in mobility; (3) a mobile multi-modal segment; (4) and a segment depending on public transport and other services. Second, we examined the single factors used in the reviewed segmentation studies, with focus on whether there is evidence in the literature for the factors’ effect on older people's travel behaviour. Based on this, we proposed a theoretical model on how the different determinants work together to form the four mobility patterns related to the identified segments. Finally, based on current trends and expectations, we assessed which segments are likely to increase or decrease in future generations of older people and what should be done to support the multi-optional and independent mobility of older people.     

Commuter impacts and behavior changes during a temporary freeway closure: the ‘Fix I-5’ project in Sacramento,California

One mile of Interstate 5 (I-5) in downtown Sacramento, California was closed intermittently for reconstruction (‘the Fix project’) over nine weeks in 2008. We analyze the impacts of the Fix on commuters’ travel behavior, as measured through two contemporaneous Internet-based surveys. The impacts of the Fix on traffic conditions do not appear to have been excessive: majorities in all relevant subsamples did not find conditions worse than usual, and sizable minorities actually found them to be better. Among the active changes to commute trips, the easiest options – avoiding rush hour and changing route – were the most common (adopted by 48% and 44%, respectively). Among the changes that reduced vehicle-miles traveled, increasing transit use and increasing telecommuting (TC) were the most common (each adopted by 5–6% of the relevant subsample). Binary logit models of these two choices suggest that persuading current adopters to increase their frequency of use is easier than convincing nonadopters to start TC or switch to transit. Women and those in larger households were found to be more likely to increase TC and transit use. Employer support of commute alternatives significantly influenced the adoption of both strategies.     

半挂液罐车的避障运动仿真分析

为研究半挂液罐车在避障运动时液体晃动对车辆行驶稳定性的影响,采用Galerkin方法建立了罐体的液体晃动方程.根据等效原则,建立了液体晃动的质量-弹簧-阻尼等效模型.结合半挂车的刚体模型,建立了半挂液罐车动力学模型,并进行了双移线避障运动仿真分析.仿真表明:随着充液率的增加,车辆的各项行驶参数先增加再减小,在充液率k=1.0附近时,液体晃动最剧烈,对车辆的行驶稳定性影响最大,在此充液率下,随着车速的增加,液罐车先发生摆振失稳,再发生侧翻事故;而在同等工况下,在充液率k=1.8时,随着车速的增加,车辆将表现为侧翻事故.