Incentivizing alternative fuel vehicles: the influence of transport policies,attitudes and perceptions

This paper aims to evaluate the influence of policies, attitudes and perceptions when incentivizing alternative fuel vehicles. The impact of possible policies such as gasoline taxes increases, purchase price subsidies, tax exemptions, and increases in fuel recharging station availability for alternative fuelled vehicles is evaluated using hybrid choice models. The models also allow assessing the sensitivity of latent variables (i.e., attitudes and perceptions) in the car purchase behaviour. The models are estimated using data from a stated choice survey collected in five Colombian cities. The latent variables are obtained from the rating of statements related to the transport system, environmental concern, vehicle preferences, and technology. The modelling approach includes regression between latent variables. Results show that environmental concern and the support for green transport policies have a positive influence on the intention to purchase alternative fuel vehicles. Meanwhile, people who reveal to be car-dependent prefer to buy standard fuelled vehicles. The analysis among cities shows similar trends in individual behaviour, although there are differences in attribute sensitivities. The policy scenario analysis revealed high sensitivity to capital cost and the need for extensive investments in refuelling stations for alternative fuel vehicles to become attractive. Nevertheless, all policies should not only be directed at infrastructure and vehicles but also be focused on user awareness and acceptance of the alternative fuel vehicles. The analysis suggests that in an environmentally conscious market, people prefer alternative fuels. However, if the transport policies support private transport, the market shares of alternative fuel vehicles will decrease.     

Phytodetritus deposited on the Antarctic shelf and upper slope: its relevance for the benthic system

Underwater photography was used to ascertain regional, seasonal, interannual or depth dependent variations in the occurrence of phytodetritus on the Antarctic seafloor in order to explain the patchy distribution patterns of the benthos. The information was obtained from an average of 63 photographs taken at each of 76 stations in the Weddell and Lazarev Sea along a 2300 km coastline during four austral summers between 1986 and 1991. In areas where the shelf was broader than 80 km, the sediment showed a significantly higher phytodetritus cover than on the narrower shelf. This can probably be explained by the lower current velocity on the broader shelf. Significantly higher percentages of phytodetritus cover were also found on the seafloor in areas where the megabenthos cover was relatively low. These results indicate that in areas with a low current velocity, organic particles sink relatively fast onto the seafloor where they are available mainly for deposit feeders. The generally more abundant filter feeders are better adapted to a higher current velocity which transports the particles mainly horizontally over longer periods. No significant relationships were found between other physical parameters and the occurrence of phytodetritus. Therefore, the results are also discussed under the aspect of a weak pelagic–benthic coupling, effected by the long-term development of the benthic system.     

不规则结构面剪切特性试验研究

为对岩体工程中不规则结构面力学特性进行基础性研究,选取N.R.Barton提出的10条标准剖面线中的第1、4、6、8、10条模拟结构面的表面形态对水泥砂浆试件进行不同法向应力水平下的常规剪切试验,并在对试验数据对结构面的剪切特性和剪切扩容现象进行深入分析的基础上,提出了适合水泥砂浆材料的抗剪强度经验公式和反正切函数的结构面剪切特性方程.研究结果表明:粗糙系数越大或法向应力越大,结构面越易表现为切齿破坏;粗糙系数越大或法向应力越小,结构面越易表现出扩容现象.      

Weekly activity-travel behaviour in rural Northern Ireland: differences by context and socio-demographic

Despite a wide variation in access to goods and services between rural areas, common policy interventions are often proposed in Northern Ireland. Questions remain as to the level and form of policy differentiation that is required, if any, both within and between different rural areas. This issue is investigated in this paper through the analysis of activity-travel patterns of individuals living in two rural areas with different levels of area accessibility and area mobility. Three focus groups, 299 questionnaires and 89 activity-travel diaries for 7 days were collected for individuals from these areas. Regression analyses were employed to explore the degree to which different factors influence activity-travel behaviour. The results indicate that individuals from rural areas with a higher level of accessibility are more integrated within their local community and as a result, are potentially less at risk of being excluded from society due to immobility. Differences, however, were also found between different groups within an area (e.g. non-car owning individuals who were more reliant on walking, and low-income individuals who made trips of a shorter distance). Based on the study findings and a review of existing policies, this research highlights the need to tailor policy responses to reflect the particular sets of circumstances exhibited in different areas.     

Assessing the influence of indicators’ complexity on hybrid discrete choice model estimates

Transportation - Hybrid discrete choice (HDC) modeling requires indicators to allow for the identification of latent variables. An indicator usually expresses the level of agreement of a respondent...     

Evaluating the use of an urban consolidation centre and electric vehicles in central London

The paper focuses on the role that can be played by urban consolidation centres (UCCs) in reducing freight traffic and its environmental impacts in towns and cities. It is based on the before and after evaluation of a trial led by a major stationery and office supplies company in which urban freight deliveries in central London made from a depot in the suburbs using diesel vehicles were replaced with the use of an urban micro-consolidation centre located in the delivery area together with the use of electrically-assisted cargo tricycles and electric vans. The results show that the total distance travelled and the CO₂eq emissions per parcel delivered fell by 20% and 54% respectively as a result of this delivery system. However, the evaluation has also indicated that the distance travelled per parcel rose substantially in the City of London delivery area as a result of the electric vehicles having far smaller load limits in both weight and volume compared with diesel vans. But, at the same time, the trial system was able to virtually eliminate CO₂eq emissions per parcel delivered in the City of London. The trial proved successful from the company's perspective in transport, environmental and financial terms. The company therefore decided to continue the operation beyond the end of the trial with it being officially launched during 2010.     

我的备用车是蝙蝠战车

德文GTX勇闯哥谭镇嘿,你是蝙蝠侠?一阵外来客的叫嚷声从一辆敞篷观光巴士的上层传来。人们纷纷向停在路边的跑车行注目礼,车身如钢琴漆般亮黑,像极了蝙蝠侠的座驾。斯科特·德文觉得开这玩笑的人真是够糊涂,他抬头瞥了一眼巴士顶上的露天座位,进出一个电力达上千瓦的微笑,然后毫无表情地说:对,我就是。     

Using best–worst scaling to identify barriers to walkability: a study of Porto Alegre,Brazil

This paper pursues three goals: (1) determining the relative importance of built environment barriers limiting walkability, (2) analyzing the existence of an asymmetry in the way people evaluate positive and negative built environment characteristics, and (3) identifying solutions to tackle the main barriers and quantify their impact in walkability. A best–worst scaling survey was developed to compare the importance of eight different attributes of the built environment regarding walkability. Model results show an asymmetry negative–positive in the judgment and choice of built environment characteristics that promote and impede walkability. The most important barriers, obtained from worst responses, are connectivity, topography, sidewalk surface and absence of policemen. Walkability scores were computed for different neighbourhoods and different policy scenarios were forecasted. Simulation results from the worst responses indicate that improvements in sidewalk quality, along with an increase in the number of police officers, lead to an 85% increase in the walkability score for the lower income neighbourhoods.

     

The provision of home to school transport in Northern Ireland

The provision of home to school transport is an important element of transport policy in local communities. This paper examines the provision of home to school transport in Northern Ireland. It reviews the nature of demand and provision, and the costs involved in providing the current system of home to school transport compared to other parts of the UK. In addition it also discusses issues surrounding the use of the statutory walking distance, safety on buses including the provision of ‘3 for 2’, standing on buses and seatbelts in Northern Ireland.     

Modelling with joint choice of ports and countries of origin and destination: application to Colombian ports

Literature has focused on studying port choice independently or as an element of a supply chain without considering the joint selection with the country of origin/destination of the imports/exports. However, the characteristics and location of a port may make it more attractive to mobilise more freight from/to some particular countries rather than others, making the port choice decision dependent on the country of origin/destination of the cargo. This article proposes advanced econometric models to evaluate simultaneously port choice and the country of origin/destination choice for Colombian imports and exports. Findings suggest that for imports and exports domestic freight rate is the most important variable for the joint choice process. Also, for exports, maritime transit time is more relevant than for imports, while for the frequency of shipping lines the opposite is true. The existence of a trade agreement and the gross domestic product per capita also have a significant influence on the election of a country for exports/imports.