Vol 19 No 2 (2019)
Vol 19 No 2 (2019)
Articles
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Table of content of Volume 19, Issue (2)
Table of content of Volume 19, Issue (2)
Table of content of Volume 19, Issue (2)
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By 2045, Sweden is to have zero net emissions of greenhouse gases. To reach this goal, stakeholders involved in planning and construction of Swedish transport infrastructure aim to half their climate impact by 2030. Planning for emission reduction measures require network level studies showing environmental impacts of the infrastructure network. Previous studies do not allow assessment of current hotspots in the infrastructure network, which limits their relevance for decision-support in this question. The aim of this paper is to assess the current annual climate impact and primary energy use of Swedish transport infrastructure by using a methodological approach based on life cycle assessment. The scope includes new construction and management (operation, maintenance, and reinvestment) of existing roads, railways, airports, ports, and fairway channels. The annual climate impact was estimated to 2.8 million tonnes carbon dioxide equivalents and the annual primary energy use was estimated to 27 terawatt hours. Mainly road and rail infrastructure contributed to these impacts. Environmental hotspots of the infrastructure network were management of the infrastructure stock (particularly reinvestment of road and rail infrastructure) and material production (particularly production of asphalt, steel, and concrete). If climate targets are to be met, these areas are particularly important to address. Additional research on impacts of small construction measures, the size of biogenic carbon emissions (in standing biomass as well as soil carbon), and the use and impacts of asphalt for road construction and management would further increase the understanding of impacts related to Swedish transport infrastructure at the network level.
By 2045, Sweden is to have zero net emissions of greenhouse gases. To reach this goal, stakeholders involved in planning and construction of Swedish transport infrastructure aim to half their climate impact by 2030. Planning for emission reduction measures require network level studies showing environmental impacts of the infrastructure network. Previous studies do not allow assessment of current hotspots in the infrastructure network, which limits their relevance for decision-support in this question. The aim of this paper is to assess the current annual climate impact and primary energy use of Swedish transport infrastructure by using a methodological approach based on life cycle assessment. The scope includes new construction and management (operation, maintenance, and reinvestment) of existing roads, railways, airports, ports, and fairway channels. The annual climate impact was estimated to 2.8...
By 2045, Sweden is to have zero net emissions of greenhouse gases. To reach this goal, stakeholders involved in planning and construction of Swedish transport infrastructure aim to half their climate impact by...
Carolina Liljenström, Susanna Toller, Jonas Åkerman, Anna Björklund -
The objective of this paper is to propose a method to analyse and describe cyclists’ behaviour at signalized intersections with specific focus on the multichannel (multi-lane) queue phenomenon. As we observed, cyclists form queues without a fixed-lane and FIFO discipline, for which the classical, car-oriented analytical approach becomes insufficient. Cyclists’ multichannel queueing behaviour is common and characterized by substantial degree of variability, especially in case of shorter queues which emerge regularly at cycle crossings. Although cyclist behaviour has been widely studied by transportation research community, their queueing behaviour picture is still incomplete. Namely, there is no method addressed to analyse the full scope of these phenomena and to quantify their impact on the cyclist queue performance.
To bridge this gap, we introduce the technique to observe multichannel queues and report relevant observations, which we then complement with a methodological framework to analyse obtained results and provide a complete multichannel queue description. We video-record cyclists as they enqueue to one of multiple channels, form the queue and smoothly merge into a single lane again as the queue discharges. We apply the method to analyse results from a pilot study of 160 cyclists forming 50 queues in the city of Krakow, Poland. The proposed method allows us to analyse and quantify the observed queue performance and its characteristics: the number of channels, their emergence process, channel and queue lengths, discharge process with FIFO violations, starting and discharging times. Findings from pilot study reveal that both queue length and discharge times strongly depend on queue formation process.
The contribution of this paper is the method to describe multichannel cyclist queueing behaviour, enriching current picture of bicycle flow and cyclists’ behaviour. Since the method has been developed on relatively short queues (up to 10 cyclists), findings included in this paper primarily refer to such queue sizes. Nonetheless, the method is formulated in a generic way, applicable also for longer bicycle queues. Possible practical implications are new estimates for queue lengths and discharge times - useful for bicycle infrastructure design and traffic engineering purposes.
The objective of this paper is to propose a method to analyse and describe cyclists’ behaviour at signalized intersections with specific focus on the multichannel (multi-lane) queue phenomenon. As we observed, cyclists form queues without a fixed-lane and FIFO discipline, for which the classical, car-oriented analytical approach becomes insufficient. Cyclists’ multichannel queueing behaviour is common and characterized by substantial degree of variability, especially in case of shorter queues which emerge regularly at cycle crossings. Although cyclist behaviour has been widely studied by transportation research community, their queueing behaviour picture is still incomplete. Namely, there is no method addressed to analyse the full scope of these phenomena and to quantify their impact on the cyclist queue performance.
To bridge this gap, we introduce the technique to observe multichannel...
The objective of this paper is to propose a method to analyse and describe cyclists’ behaviour at signalized intersections with specific focus on the multichannel (multi-lane) queue phenomenon. As we observed,...
Rafał Kucharski, Arkadiusz Drabicki, Klaudia Żyłka, Andrzej Szarata -
Although Connected Vehicle technology is developing rapidly, connected vehicles (CV) are going to mix with the traditional vehicles (i.e., non-connected vehicles) for a long time. The effects of deploying CV on urban traffic systems are actually not clear. The main objective of this study is to evaluate the potential effects of route guidance under connected vehicle environment on an urban traffic network in terms of traffic mobility and safety. Microscopic simulation approach is used to conduct CV environment simulation and the rolling horizon approach is used for information updating among the connected vehicles. Meanwhile, driving behavior is modeled through aggressiveness and awareness of drivers. Traffic mobility for the road network was measured by average trip time and average vehicle trip speed. A surrogate measure, i.e., the time-to-collision involved incident rate for one kilometer driven, was used to assess the safety of the road network. Based on a real urban traffic network, the impacts of market penetration levels of connected vehicles and information updating intervals were studied. Simulation results showed that market penetration level of connected vehicles has little impact on the mobility and safety of road network. In addition, according to the simulation conducted in this paper, shorter updating interval is shown to be likely to lead to better mobility, while the safety of road network is likely to decline, under the assumptions embraced in the simulation. By contrast, the simulation also showed that longer updating interval is likely to lead to better safety and decreased mobility.
Although Connected Vehicle technology is developing rapidly, connected vehicles (CV) are going to mix with the traditional vehicles (i.e., non-connected vehicles) for a long time. The effects of deploying CV on urban traffic systems are actually not clear. The main objective of this study is to evaluate the potential effects of route guidance under connected vehicle environment on an urban traffic network in terms of traffic mobility and safety. Microscopic simulation approach is used to conduct CV environment simulation and the rolling horizon approach is used for information updating among the connected vehicles. Meanwhile, driving behavior is modeled through aggressiveness and awareness of drivers. Traffic mobility for the road network was measured by average trip time and average vehicle trip speed. A surrogate measure, i.e., the time-to-collision involved incident rate for one kilometer...
Although Connected Vehicle technology is developing rapidly, connected vehicles (CV) are going to mix with the traditional vehicles (i.e., non-connected vehicles) for a long time. The effects of deploying CV on...
Zhao Liu, Jianhua Guo, Lei Chen, Yun Wei, Wei Huang, Jinde Cao