| 1. |
- Bergman, Astrid, et al.
(författare)
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Analytical traffic models for roundabouts with pedestrian crossings
- 2011
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Ingår i: Procedia - Social and Behavioral Sciences. - : Elsevier BV. - 1877-0428. ; 16, s. 697-708
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Tidskriftsartikel (refereegranskat)abstract
- Roundabouts have become a more common type of intersection in Sweden over the last 30 years. In order to evaluate the roundabout level-of-service both analytical models and simulation models are being used. Analytical traffic models for intersections, such as the Swedish capacity model Capcal, has difficulties estimating the level-of-service of a roundabout if there are pedestrians and cyclists at crossings located close to the roundabout. It is well known that a crossing located after a roundabout exit can cause an up-stream blocking effect that affects the performance of the roundabout. But how the upstream blocking effect depends on the different flows of vehicles and pedestrians is not known. In this paper an existing analytical model by Rodegerdts and Blackwelder has been investigated and compared to simulations in VISSIM and measurements from Swedish roundabouts. The purpose of this investigation is to examine if the model by Rodegerdts and Blackwelder is suitable for implementing into existing analytical models such as Capcal. The results show that the model by Rodegerdts and Blackwelder can estimate if a capacity loss will occur, but the magnitude of this loss is more difficult to evaluate. The conclusion and recommendation is that the model by Rodegerdts and Blackwelder should be implemented into the Swedish capacity model Capcal. The model by Rodegerdts and Blackwelder is to be used as a warning system if the results in Capcal are too uncertain to use for analysis of the roundabout performance.
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| 2. |
- Olstam, Johan, 1979-, et al.
(författare)
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A review of guidelines for applying traffic simulation to level-of-service analysis
- 2011
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Ingår i: Procedia - Social and Behavioral Sciences. - : Elsevier. - 1877-0428. ; 16, s. 771-780
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Tidskriftsartikel (refereegranskat)abstract
- Microscopic traffic simulation is often used as an alternative or complementary tool to analytical methods and procedures for level-of-service analyses of road traffic facilities. The increased usage of traffic simulation for level-of-service analysis has raised a need for guidelines on how to apply and use traffic simulation models. Many countries have developed or are currently developing traffic simulation guidelines. This is also the case in Sweden, were the new Swedish highway capacity manual will include a chapter on traffic simulation. This paper presents a survey of the current traffic simulation guidelines in USA, Germany, UK, Denmark and Sweden. The guidelines have been analysed with respect to the aspects covered: when to apply simulation; the workflow of a simulation study; data collection needs; calibration and validation; experimental design; statistical analysis; and calculation of level-of-service measures. The guidelines analysed are focused on different aspects and none of them covers all of the topics listed above. Some of the guidelines are connected to specific simulation software packages and some are written in a more general manner. Most of the aspects covered are general and applicable in any country. The main reason for developing country specific guidelines is often a need for guidelines in the local language. Experimental design and statistical analysis are not treated extensively in the guidelines; neither do the guidelines discuss how to deal with calibration based on limited real world measurements. Calculation of level-of-service measures are quite extensively treated in some of the guidelines and to a little extent in others. All of the guidelines contain important contributions for the simulation chapter of the new Swedish highway capacity manual.
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| 3. |
- Nurhadi, Lisiana, et al.
(författare)
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Advancing from efficiency to sustainability in Swedish medium-sized cities : an approach for recommending powertrains and energy carriers for public bus transport systems
- 2014
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Konferensbidrag (refereegranskat)abstract
- European national, regional, and local authorities have started to take action to make public bus transport services more effective and less polluting. Some see the possibility to move beyond a narrow focus on efficiency or carbon dioxide reductions towards an integrated sustainability perspective. This paper uses this perspective to build and test a new assessment approach that should enhance decisions on bus transport powertrains and energy carriers for Swedish medium-sized cities. The study suggests that a superiority of electric powertrains is revealed if a traditional economic analysis is integrated with a strategic sustainability perspective.
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