scholarly journals Shifting perspectives: A comparison of travel-time-based and carbon-based accessibility landscapes

2021 ◽  
Vol 14 (1) ◽  
pp. 345-365
Author(s):  
Julia Kinigadner ◽  
David Vale ◽  
Benjamin Büttner ◽  
Gebhard Wulfhorst

Undoubtedly, climate change and its mitigation have emerged as main topics in public discourse. While accessibility planning is recognized for supporting sustainable urban and transport development in general, the specific challenge of reducing transport-related greenhouse gas emissions has rarely been directly addressed. Traditionally, accessibility is operationalized in line with the user perception of the transport system. Travel-time-based measures are considered to be closely linked with travel behavior theory, whereas CO2 emissions are not necessarily a major determinant of travel decisions. Given the changed prioritization of objectives, additional emphasis should be placed on the environmental costs of travel rather than solely the user costs. Accessibility analysis could account for this shift in perspectives by using CO2 emissions instead of travel time in the underlying cost function. While losing predictive power in terms of travel behavior compared to other implementations of accessibility, carbon-based accessibility analysis enables a normative understanding of travel behavior as it ought to be. An application in the Munich region visualizes the differences between travel-time-based and carbon-based accessibility by location, transport mode, and specification of the accessibility measure. The emerging accessibility landscapes illustrate the ability of carbon-based accessibility analysis to provide new insights into land use and transport systems from a different perspective. Based on this exercise, several use cases in the context of low-carbon mobility planning are discussed and pathways to further develop and test the method in cooperation with decision-makers are outlined.

2008 ◽  
Vol 2085 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Tony E. Smith ◽  
Chao-Che Hsu ◽  
Yueh-Ling Hsu

Although time constraints on travel behavior have been widely recognized, little effort has been made to incorporate such constraints into the traditional stochastic user equilibrium (SUE) framework. The major objective of this research is to fill this gap by incorporating travel time constraints into the SUE model by means of a nonlinear perceived travel time function. This modified model, designated the travel time budget model, focuses primarily on discretionary travel behavior (such as shopping trips) and hence also allows the possibility of deferring travel decisions by incorporating an additional choice alternative designated the shop-less-frequently alternative. This model is compared with the traditional SUE model by using a simulated travel scenario on a test network designed to reflect a practical planning situation. The simulation shows that when attractiveness levels are increased by the introduction of a new shopping opportunity, the presence of travel time constraints can lead to significantly smaller predicted travel volumes than those of the traditional SUE model. More important, it shows that the overall pattern of travel can be quite different. In particular, travel to the shopping destination with enhanced attractiveness can actually decrease for some origin locations. The findings suggest that when an attempt is made to evaluate the impact of planning alternatives on future traffic patterns, it is vital to consider not only the cost of time itself but also the time trade-offs between travel and other human activities.


Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 137
Author(s):  
Xianchun Tan ◽  
Tangqi Tu ◽  
Baihe Gu ◽  
Yuan Zeng ◽  
Tianhang Huang ◽  
...  

Assessing transport CO2 emissions is important in the development of low-carbon strategies, but studies based on mixed land use are rare. This study assessed CO2 emissions from passenger transport in traffic analysis zones (TAZs) at the community level, based on a combination of the mixed-use development model and the vehicle emission calculation model. Based on mixed land use and transport accessibility, the mixed-use development model was adopted to estimate travel demand, including travel modes and distances. As a leading low-carbon city project of international cooperation in China, Shenzhen International Low-Carbon City Core Area was chosen as a case study. The results clearly illustrate travel demand and CO2 emissions of different travel modes between communities and show that car trips account for the vast majority of emissions in all types of travel modes in each community. Spatial emission differences are prominently associated with inadequately mixed land use layouts and unbalanced transport accessibility. The findings demonstrate the significance of the mixed land use and associated job-housing balance in reducing passenger CO2 emissions from passenger transport, especially in per capita emissions. Policy implications are given based on the results to facilitate sophisticated transport emission control at a finer spatial scale. This new framework can be used for assessing the impacts of urban planning on transport emissions to promote sustainable urbanization in developing countries.


2021 ◽  
Vol 13 (4) ◽  
pp. 2418
Author(s):  
Ana María Arbeláez Vélez ◽  
Andrius Plepys

Shared mobility options, such as car sharing, are often claimed to be more sustainable, although evidence at an individual or city level may contradict these claims. This study aims to improve understanding of the effects of car sharing on transport-related emissions at an individual and city level. This is done by quantifying the greenhouse gas (GHG) emissions of the travel habits of individuals before and after engaging with car sharing. The analysis uses a well-to-wheel (WTW) approach, including both business-to-consumer (B2C) and peer-to-peer (P2P) car-sharing fleets. Changes in GHG emissions after engaging in car sharing vary among individuals. Transport-related GHG emissions caused by car-free individuals tend to increase after they engage in car sharing, while emissions caused by previous car owners tend to fall. At the city level, GHG emissions savings can be achieved by using more efficient cars in sharing systems and by implementing greener mobility policies. Changes in travel habits might help to reduce GHG emissions, providing individuals migrate to low-carbon transport modes. The findings can be used to support the development and implementation of transport policies that deter car ownership and support shared mobility solutions that are integrated in city transport systems.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1161
Author(s):  
Maedeh Rahnama Mobarakeh ◽  
Miguel Santos Silva ◽  
Thomas Kienberger

The pulp and paper (P&P) sector is a dynamic manufacturing industry and plays an essential role in the Austrian economy. However, the sector, which consumes about 20 TWh of final energy, is responsible for 7% of Austria’s industrial CO2 emissions. This study, intending to assess the potential for improving energy efficiency and reducing emissions in the Austrian context in the P&P sector, uses a bottom-up approach model. The model is applied to analyze the energy consumption (heat and electricity) and CO2 emissions in the main processes, related to the P&P production from virgin or recycled fibers. Afterward, technological options to reduce energy consumption and fossil CO2 emissions for P&P production are investigated, and various low-carbon technologies are applied to the model. For each of the selected technologies, the potential of emission reduction and energy savings up to 2050 is estimated. Finally, a series of low-carbon technology-based scenarios are developed and evaluated. These scenarios’ content is based on the improvement potential associated with the various processes of different paper grades. The results reveal that the investigated technologies applied in the production process (chemical pulping and paper drying) have a minor impact on CO2 emission reduction (maximum 10% due to applying an impulse dryer). In contrast, steam supply electrification, by replacing fossil fuel boilers with direct heat supply (such as commercial electric boilers or heat pumps), enables reducing emissions by up to 75%. This means that the goal of 100% CO2 emission reduction by 2050 cannot be reached with one method alone. Consequently, a combination of technologies, particularly with the electrification of the steam supply, along with the use of carbon-free electricity generated by renewable energy, appears to be essential.


2021 ◽  
Vol 5 (1) ◽  
pp. 25
Author(s):  
Souhir Abbes

In this paper, we use the Logarithmic Mean Divisia Index (LMDI) to apply decomposition analysis on Carbon Dioxide (CO2) emissions from transport systems in seven Eastern European countries over the period between 2005 and 2015. The results show that “economic activity” is the main factor responsible for CO2 emissions in all the countries in our sample. The second factor causing increase in CO2 emissions is the “fuel mix” by type and mode of transport. Modal share and energy intensity affect the growth of CO2 emissions but in a less significant way. Finally, only the “population” and “emission coefficient” variables slowed the growth of these emissions in all the countries, except for Slovenia, where the population variable was found to be responsible for the increase in CO2 emissions. These results not only contribute to advancing the existing literature but also provide important policy recommendations.


2021 ◽  
Vol 10 ◽  
pp. 100347
Author(s):  
Lorenzo Stilo ◽  
Diana Segura-Velandia ◽  
Heinz Lugo ◽  
Paul P. Conway ◽  
Andrew A. West

2020 ◽  
Vol 12 (7) ◽  
pp. 2851 ◽  
Author(s):  
Sheng-Hsiung Chiu ◽  
Tzu-Yu Lin ◽  
Hai-Lan Yang

Sustainable development has always been an important issue for all policy makers, even more so now, as global warming has seriously threatened the whole world. To understand the efficacy of regional sustainable policies, we proposed a dynamic, two-stage, slacks-based measure (SBM) model with carry-over and intermediate variables, highlighting the importance of an electricity portfolio, to measure overall energy performance for the purpose of regional sustainable development. In this unified linear programming framework with intertemporal evaluation, we estimated the effects of a clean electricity supply by the abatement of CO2 emissions and the gain of economic growth. The results can be used as a reference for decision makers to shape regional sustainable development policies. Using data of 30 provincial administration regions in China for the period of 2012–2017, we postulate that the lower energy performance of the Chinese regional economic system for sustainable development may be attributed to a lower electricity portfolio performance. We then postulate that investment in low-carbon energy infrastructure can combat CO2 emissions, and is also a major driving force in the regional economic growth.


2018 ◽  
Vol 30 (6) ◽  
pp. 721-731 ◽  
Author(s):  
Diamanto Mintzia ◽  
Fotini Kehagia ◽  
Anastasios Tsakalidis ◽  
Efthimios Zervas

Low-carbon transport is a priority in addressing climate change. Transport is still almost totally dependent on fossil fuels (96%) and accounts for almost 60% of global oil use. Sustainable transport systems, both passenger and freight, should be economically and technically feasible, but also low-carbon and environmentally friendly. The calculation of greenhouse gas emissions in transport projects is becoming a primary target of transport companies as a part of an endeavor for low-carbon strategies to reduce the energy demand and environmental impact. This paper investigates the CO2 impact of construction and operation of the main highway and railway line infrastructure in Greece, which connects Athens and Thessaloniki, the capital and the second biggest city in Greece respectively and provides a comparative analysis in roadway and railway transport.


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