Road transport-related energy consumption: Analysis of driving factors in Tunisia

The rapid growth of urban population and the development of road infrastructures in Tunisian cities have brought about many environmental and economic problems, including the rise scored in energy consumption and the increase in the quantity of gas emissions arising from road transport. Despite the critical nature of such problems, no policies have yet been adopted to improve energy efficiency in the transport sector. This paper aims to determine driving factors of energy consumption change for the road mode. It uses decomposition analysis to discuss the effects of economic, demographic and urban factors on the evolution of transport energy consumption. The main result highlighted in the present work is that vehicle fuel intensity, vehicle intensity, GDP per capita, urbanized kilometers and national road network are found to be the main drivers of energy consumption change in the road transport sector during 1990–2006 period. Consequently, several strategies can be elaborated to reduce road transport energy. Economic, fiscal and regulatory instruments can be applied in order to make road transport more sustainable.     

Trends of energy efficiency in Finnish road freight transport 1995–2009 and forecast to 2016

A framework for modeling and analyzing the energy efficiency of road freight transport is presented in this paper. This framework is tested by using the data from the Finnish Goods Transport by Road statistics. The data was enhanced by calculating the fuel consumption for each trip in the data. To calculate this, weight-fuel consumption functions were estimated for each Euro-class vehicles and road type. This is a new method for analyzing the energy efficiency of road freight transport and it could be applied also in other countries gathering freight transport data with continuous company surveys. The analysis show that the energy efficiency of road freight transport in Finland improved during 1995–2002, but has declined since. The major drivers in the development have been the changes in the level of empty running and vehicle fuel efficiency. Extrapolating current statistical trends of factors that influence the energy efficiency show that the target set by the Finnish government for improving energy efficiency by 9% until 2016 will not be achieved. However, the target is possible to be achieved by a combination of small changes to some determinants.     

Decomposing road freight energy use in the United Kingdom

Applying the techniques of decomposition analysis we estimate the relative contribution of ten variables (termed ‘key ratios’) plus GDP to the change in UK road freight energy use over the period 1989–2004 inclusive. The results are best interpreted as an estimate of the percentage growth in energy consumption that would have resulted from the change in the relevant factor (e.g. length of haul) had the other factors remained unchanged. The results demonstrate that the main factor contributing to the decoupling of UK road freight energy consumption from GDP was the decline in the value of domestically manufactured goods relative to GDP. Over the period 1989–2004 this largely offset the effect of increases in GDP on road freight energy consumption. While the decline in domestic manufacturing was to some extent displaced by increases in imports, the net effect of these supply factors, together with shifts in the commodity mix, has been to reduce UK road freight energy consumption by 30.1%. The net effect on global carbon dioxide (CO₂) emissions is likely to be somewhat less beneficial, since many freight movements associated with the manufacture of imported goods have simply been displaced to other countries.     

Trends in road freight transportation carbon dioxide emissions and policies in China

We adopted the simple average Divisia index approach to explore the impacts of factors on the carbon dioxide (CO₂) emissions from road freight transportation in China from 1985 to 2007. CO₂ emissions were investigated using the following as influencing factors: the emission coefficient, vehicle fuel intensity, working vehicle stock per freight transport operator, market concentration level, freight transportation distance, market share of road freight transportation, ton-kilometer per value added of industry, industrialization level and economic growth. Building on the results, we suggest that economic growth is the most important factor in increasing CO₂ emissions, whereas the ton-kilometer per value added of industry and the market concentration level contribute significantly to decreasing CO₂ emissions. We also discussed some recent important policies concerning factors contained in the decomposition model.     

A thermodynamic,environmental and material flow analysis of the Italian highway and railway transport systems

The goal of this work is to provide a multi-method multi-scale comparative picture of selected terrestrial transport modalities. This is achieved by investigating the Italian transportation system by means of four different evaluation methods: material flow accounting (MFA), embodied energy analysis (EEA), exergy analysis (EXA) and emergy synthesis (ES). The case study is the main Italian transportation infrastructure, composed by highways, railways, and high-speed railways (high-speed trains, HST) sub-systems supporting both passengers and freight transport. All the analyses have been performed based on a common database of material, labor, energy and fuel input flows used in the construction, maintenance and yearly use of roads, railways and vehicles. Specific matter and energy intensities of both passenger and freight transportation services were calculated factors affecting results as well as strength and weakness points of each transportation modality were also stressed. Results pointed out that the most important factors in determining the acceptability of a transportation system are not only the specific fuel consumption and the energy and material costs of vehicles, as it is common belief, but also the energy and material costs for infrastructure construction as well as its intensity of use (with special focus on load factor of vehicles). The latter become the dominant factors in HST modality, due to technological and safety reasons that require high energy-cost materials and low intensity of traffic. This translates into very high thermodynamic and environmental costs for passenger and freight transported, among which an embodied energy demand up to 1.44 MJ/p-km and 3.09 MJ/t-km, respectively.     

Trends in passenger transport and freight energy use in Spain

This paper provides for the first time a complete analysis of recent trends in activity, carbon emissions, modal shares, energy intensities, vehicle use and fuels in the Spanish transport system from 1990 to 2008 and discusses policy options. Passenger and freight activities have increased in Spain and are projected to continue, presenting a challenge for sustainable mobility efforts; emissions have increased, mainly fueled by the rise in activity; modal shares have pulled away from public transport, with a decrease in bus and rail, towards an increase in car and air travel; energy intensities, though initially decreasing, are currently increasing; and fuel use has taken over 37% of Spanish final energy consumption.     

Trends in truck freight energy use and carbon emissions in selected OECD countries from 1973 to 2005

Trends in truck freight energy use and carbon emissions

In the age of global supply chains and “just in time” logistics, fast and efficient goods movement is often seen as an economic imperative. Growth in global goods movement not only translates into growth in commercial trucking activity but also into growth in the share of trucking compared to other modes of in-country freight transportation. These trends have a significant impact on the energy intensity of freight transport. Using a bottom-up approach relying on national data, this study compares the energy intensity of truck freight in Australia, France, Japan, the United Kingdom and the United States from 1973 to the present. The analysis builds on previous work by Schipper et al. (1997) and Schipper and Marie-Lilliu (1999) decomposing energy use for freight. Intensity is expressed in terms of vehicle intensity (megajoules/vehicle-kilometer), modal energy intensity (megajoules/tonne-kilometer), and carbon intensity (grams/tonne-km). The cross-country comparison highlights in part the influence of geography, transportation infrastructure, and truck utilization patterns on energy and carbon intensity from this sector. While improving fuel economy of individual vehicles is very important, large reductions in trucking energy use and emissions will also come from better logistics and driving, higher load factors, and better matching of truck capacity to load.     

A case study in data audit and modelling methodology—Australia

The purpose of the paper is to outline a rigorous, spatially consistent and cost-effective transport planning tool that projects travel demand, energy and emissions for all modes associated with domestic and international transport. The planning tool (Aus_eTran) is a multi-modal, multi-fuel and multi-regional macroeconomic and demographic-based computational model of the Australian transport sector that overcomes some of the gaps associated with existing strategic level transport emission models. The paper also identifies a number of key data issues that need to be resolved prior to model development with particular reference to the Australian environment. The strategic model structure endogenously derives transport demand, energy and emissions by jurisdiction, vehicle type, emission type and transport service for both freight and passenger transport. Importantly, the analytical framework delineates the national transport task, energy consumed and emissions according to region, state/territory of origin and jurisdictional protocols, provides an audit mechanism for the evaluation of the methodological framework, integrates a mathematical protocol to derive time series FFC emission factors and allows for the impact of non-registered road vehicles on transport, fuel and emissions.     

Energy and transport in comparison: Immaterialisation,dematerialisation and decarbonisation in the EU15 between 1970 and 2000

This article compares the development of transport and energy use with a focus on carbon dioxide (CO₂) emissions in the EU15 countries between 1960 and 2000, and separately by each individual EU country between 1970 and 2000. Based on a review on the literature, immaterialisation can be defined as the reduction of energy intensity and transport intensity; dematerialisation can be defined as the reduction in carbon intensity of energy production and the carbon intensity of transport; decarbonisation can be defined as the reduction in (total and transport) carbon intensity of the whole economy. Although there is a clear pattern of reduction in energy intensity of the economy and carbon intensity of energy production, a similar pattern cannot be found in transport. Neither the transport intensity of the economy nor the carbon intensity of transport has been reduced. In particular, freight transport intensity has grown between 1985 and 2000. Data presented by country have shown even more variation. The EU15 countries were aggregated into six groups by cluster analysis to establish the different patterns on each of the three measures. It is concluded that the EU15 countries will have problems in achieving the EU White Paper target of decoupling transport growth from economic growth and the Kyoto target of reducing total CO₂ emissions by 8% from the 1990 level between 2008 and 2012. However, there are some weak signals suggesting a more sustainable passenger transport system.     

Emissions of CO2 from road freight transport in London: Trends and policies for long run reductions

Freight transport has been receiving increasing attention in both literature and practice following the growing recognition of its importance in urban transport planning. This paper analyses historical and projected road freight CO₂ emissions in the city of London and explores the potential mitigation effect of a set of freight transport policies and logistics solutions. Findings indicate a range of policies with potential to reduce emissions in the period up to 2050. However, this reduction would appear to only be capable of partly counterbalancing the projected increase in freight traffic. More profound behavioural measures therefore appear to be necessary for London’s CO₂ emissions reduction targets to be met.     

Estimating road transport fuel consumption in Ecuador

Road transport is one of the sectors with highest energy consumptions in the planet, with large dependence of fossil fuels, and contribution for global greenhouse gas emissions. Although, Latin America is not a high-energy consumer, its share in global consumption is expected to grow, especially in the transportation sector. This make essential for developing countries the adoption of better policies to identify the vehicle groups with largest fuel demands. The present study describes the VKT technique to disaggregate road transport energy consumption by vehicle type, applied to the road transportation system of Ecuador. It also describes the procedures performed to estimate the variables required to run the model, and some of the practical applications that be used to create public policies. Results show as the biggest fuel consumers the heavy-duty freight cargo, followed by light duty vehicles. The estimation of greenhouse gas emissions evidence that road transport released 14.3 million tons of CO₂ in 2012. When fuel consumption is compared by it costs, it can be confirmed that Ecuadorean Government covered, through subsidies, for 68% of the annual fuel costs of national road transport, demonstrating the importance of restructuring these expenditures in order to achieve an efficient road transport system.     

Energy analysis and exergy utilization in the transportation sector of Jordan

The transport sector is responsible for about 37% of total final energy demand in Jordan, and thus it is considered an important driver for determining future national energy needs. This paper presents energy analysis and exergy utilization in the transportation sector of Jordan by considering the sectoral energy and exergy flows for the last two decades. The transportation sector, in Jordan, is a two-mode system, namely, road, which covers almost all domestic passenger and freight transport and airways. The latter is mainly used for international flights. The average estimated overall energy and exergy efficiencies were found as 23.2% and 22.8%, respectively. This simply indicates that there is large potential for improvement and efficiency enhancement. It is believed that the present technique is practical and useful for analyzing sectoral energy and exergy utilization to determine how efficiently energy and exergy are used in the transportation sector. It is also helpful to establish standards, based on exergy, to facilitate applications in different planning processes such as energy planning. A comparison with other countries showed that energy and exergy efficiencies of the Jordanian transport sector are slightly lower than that of Turkey, and higher than those incurred in Malaysia, Saudi Arabia and Norway. Such difference is inevitable due to dissimilar structure of the transport sector in these countries.     

基于LEAP模型的广州交通领域能耗及空气污染物排放分析

基于长期能源替代规划系统(LEAP)模型,结合情景分析法,模拟广州交通领域未来的能耗及CO、HC、NOx、PM2.5、SO2等主要空气污染物排放趋势,分析广州交通领域的节能及空气污染物排放控制策略.结果表明:综合情景下,到2035年,广州交通领域将较基准情景节能23.06％,CO、HC、NOx、PM2.5、SO2分别减...     

Backcasting sustainable freight transport systems for Europe in 2050

European freight transport emissions and fuel consumption are projected to increase. This study focuses on long distance freight transport (LDFT) and explores possible sustainable futures through quantitative modeling. The evaluation was part of European foresight process between researchers, policy makers and freight companies (FREIGHTVISION). Greenhouse gas (GHG) emissions and energy demand of road, rail and inland waterways were estimated for an EU-27 in 2005. Development was extrapolated to 2050 based on technology and freight performance forecasts. Stakeholders found the forecasted GHG emissions and fossil fuel share unsustainable, so alternative futures were developed with backcasting. The developed emission model was run with random parameter combinations to screen a set of sustainable futures, with an 80% reduction of GHG emissions and fossil fuel share. Freight transport performance was not controlled in the backcasts, but several sustainable futures were found if significant changes in transport efficiency and energy mix are implemented. In spite of agreeing on the importance of reducing emissions, stakeholders had difficulties in choosing a preferred technological future. Simple models were found to be an effective tool for communicating the influence of various measures. Further research is recommended to screen preferable technological roadmaps from the broad range of available futures.     

The rebound effect on road freight transport: Empirical evidence from Portugal

Because a large proportion of total operating costs for transportation companies goes towards energy, a reduction in energy operating costs, brought about by an increase in fleet fuel efficiency, or an increase in operational efficiency, results in a change in the relative cost of road freight transportation. This fact could result in an increase in the demand for such services. If this is true, the result would be an increase in total fuel consumption. Consequently, that part of the energy savings obtained through the increased energy efficiency would be lost. The existence of a “Rebound Effect” is especially important in the road freight transportation sector and is crucial for the definition of a national energy policy.     

Measurement of CO2 emissions from road freight transport: A review of UK experience

It is possible to estimate CO₂ emissions from road freight transport in different ways, depending on the definition of trucking activity, the degree of reliance on survey, vehicle test-cycle and traffic count data and the geographical scope of the calculation. The emergence of differing road freight-related CO₂ estimates from official sources and revisions to statistical series can frustrate the policy-making process and erode the confidence of industry stakeholders in the validity of the figures. Using UK data, this paper examines the various methods of carbon auditing road freight transport at the national level and compares the results both for a single year (2006) and over a time period. It highlights a series of statistical anomalies and approximations and tries to explain discrepancies that have arisen in the UK data sets. A concluding section considers the general lessons that can be learned from the recent UK experience in this field.     

Decomposition of intensity of energy-related CO2 emission in Chinese provinces using the LMDI method

Uncovering the driving factors of CO₂ emission intensity declining is important for China. This paper improves the logarithmic mean Divisia index technique, which includes energy density and energy consumption intensity, to explore the driving factors of carbon emission intensity (CI) in 29 Chinese provinces from 1995–2012. The main results are: (1) energy consumption intensity plays a more important role than carbon emission density (CD) for a rapid decrease in CI during the research period, so a much room is left for a significant CD reduction through carbon emission reduction technology, energy structural reduction, and energy consumption proportional reduction. (2) The decrease in energy consumption technology and energy structure in secondary industries contributes the most reduction in energy consumption intensity. (3)The energy consumption proportions of secondary and tertiary industries are the two most important drivers to decrease CD. (4) During the research period, the energy consumption proportions of secondary industries result in the most decrease in CD, whereas the energy consumption proportions of tertiary industries cause the most increase in CD.     

China on the move: Oil price explosion?

Rapid expansion of highway and jet traffic in China has created a surge of demand for oil products, putting pressure on world energy markets and petroleum product prices. This paper examines trends in freight and passenger traffic to assess how growth in China's transport demand relates to growth in China's economy, as well as the energy intensity of transport. Based on assumptions about demand elasticity and energy intensity, a range of scenarios is developed for China's oil demand through 2020. Incremental oil demand from China's transport sector is then compared with world oil demand projections to assess the likely impact on world oil prices. The finding is that new demand from China's transport sector would likely raise world oil prices in 2020 by 1–3% in reference scenarios or by 3–10% if oil supply investment is constrained.     

Policies to reduce energy use and environmental emissions in the transport sector : A case of Delhi city

This paper aims to analyze factors influencing energy consumption pattern and emission levels in the transport sector of Delhi, and extrapolates total energy demand and the vehicular emissions, using a computer-based software called ‘Long Range Energy Alternative Planning’ (LEAP) and the associated ‘Environmental Database (EDB)’. The study is restricted to passenger modes of transport in Delhi and does not include the freight model. Travel demand is first estimated by analyzing data on vehicle population, average distance travelled, and occupancy level. Next, data on travel demand, proportion of travel demand catered by road and rail, modal split, occupancy and fuel efficiency are compiled within the LEAP framework, in order to estimate the energy demand in Delhi. In addition, emission factors are compiled under EDB module of the LEAP structure to estimate the resultant pollution loading. The LEAP model is run under five alternative scenarios to estimate the current consumption of gasoline and diesel oil in Delhi and forecast the same for the years 1994/1995, 2000/2001, 2004/2005 and 2009/2010, respectively. Under each scenario, the model also estimates emissions of CO, HC, NO_x, SO₂, Pb and TSP. The total emissions are translated into concentration levels attributable to the passenger transport to get an indication of air quality in Delhi. This is accomplished by the use of proportional air quality model. Finally, scenario results are analyzed to study the impact of different urban transport policy initiatives that will reduce the growth of fuel demand and emissions. The prime objective is to arrive at an optimal transport policy that limits the future growth of fuel consumption as well as air pollution.     

Cost-optimal design and energy management of fuel cell electric trucks

Road freight transport on hilly routes represents a significant challenge for the advancement of fuel cell electric trucks because of the high-performance requirements for fuel consumption, vehicle lifetime, and battery charge control. Therefore, it is essential to optimize the vehicle design and energy management, which greatly influence the driving performance and total cost of ownership. This paper focuses on the cost-optimal design and energy management of fuel cell electric trucks, considering five key influencing factors: powertrain component sizing, driving cycle, vehicle weight, component degradation, and market prices. The cost optimization relies on a novel predictive energy management scheme based on dynamic programming and the systematic calibration of control parameters. The paper analyzes the simulation results to highlight three main findings for fuel cell electric trucks: 1) cost-optimal energy management is essential to define the best trade-off between fuel consumption and component degradation; 2) the total cost of ownership is significantly influenced by component sizing, driving cycles, vehicle weight, and market prices; 3) predictive energy management is highly beneficial in challenging road topographies for substantial cost-saving and lower component size requirements.