Vetenskapliga artiklar

Vetenskapliga artiklar

Vetenskapliga artiklar

A Method to Separate Primary and Secondary Train Delays in Past and Future Timetables Using Macroscopic Simulation

Carl-William Palmqvist, Ingrid Johansson and Hans Sipilä, Preprint submitted to Transportation Research Part B: Methodological, July, 2022

Punctuality is a key factor in railway operations, and is affected by both primary and secondary delays to differing degrees. Being able to separate these two types of delays is very important when simulating  operations, and when conducting punctuality improvement efforts. However, it is not easy to estimate the relative proportions of primary versus secondary delays using historical data. In this paper, we demonstrate a method that uses repeated runs of a macroscopic simulation tool to estimate what share of delays have been primary or secondary. Using the Swedish region of Scania as a case study, we estimate that about 36% of delays in 2019 were primary, leaving 64% as secondary. We further show that in order for operations to reach the targeted level of punctuality, 95% instead of the observed 87%, primary delays would have had to be cut by half. Using a draft timetable for 2025, we also simulate what the punctuality would be given different assumptions of primary delays. Assuming the same level of primary delays in 2025 as in 2019, we estimate that the punctuality would drop by a further 5%-points due to increased density of operations. In order to reach the punctuality target of 95% in 2025, primary delays would instead need to be reduced by two thirds. On the request of the infrastructure manager, we also show the predicted geographical distribution of secondary delays in this future timetable. Our results demonstrate the usefulness of fast and well-calibrated simulation models, contribute methodologically to the calibration of such models, and highlight the need for drastic delay reduction measures.

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Urban planning for car-free housing and ideas of future desired states

Lina Berglund-Snodgrass, Nordic Journal of Urban Studies, no.1 2022

Planning for car-free housing has emerged as a solution for accomplishing sustainable urban development. There has been a tendency among researchers and policy makers to understand car-free housing in terms of “lifestyle politics”, where change is advanced by fostering morally or socially inspired lifestyle choices. The aim of this article is to situate lifestyle politics in a context of broader urban development by analysing ideas of future desired states that underpin planning for car-free housing, so as to allow for a critical discussion around what long-term urban futures urban planning wants to accomplish through such housing. By drawing from Mukhtar-Landgren’s conceptual pair of planning object and subject, and examining documents and formal correspondence relating to four examples of planning car-free housing in Sweden, the study shows three different ideas of the future that underpin the planning which includes different assumptions of sustainable mobility, individuals and urban planning: Planning for (1) “an optimized system”, which includes assumptions of rational objects which travel efficiently; (2) “individual freedom”, which includes assumptions of independent consumers which travel rightly; and (3) “community and togetherness”, which includes assumptions of individuals being part of a community which travels less.

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The spread of passengers on platforms and dwell times for commuter trains: A case study using automatic passenger count data

Ruben A. Kuipers and Carl-William Palmqvist, original abstract submittal for TRISTAN XI Symposium, march 2022

Dwell times are considered to be one of the main constraints in terms of rail capacity, and have as much of an impact on capacity as maximum running speeds of trains (Harris, 2005). Several factors which influence dwell times have been identified in the past, such as rolling stock design (Thoreau et al., 2016), friction between boarding and alighting passengers (Seriani et al., 2019), and the volume of passengers (Palmqvist et al., 2020) for example. To add to the understanding of dwell times, the study we present here focuses on the relation between the spread of passengers on a station platform before boarding a train and dwell times. The spread of passengers, also known as concentrated boarding (Oliveira et al., 2019), has been shown to have a large impact on dwell times.

Measures to help spread out passengers more evenly between the available doors during the boarding procedure have been suggested in the past, ranging from platform markings signalling that people should spread out across to the platform as mentioned by Oliveira et al. (2019), to providing realtime information on the onboard crowding levels (Zhang et al., 2017). When implementing such measures it is not only important to understand the effectiveness of the measures itself but it is also important to understand the context in which these measures can have a beneficial effect on dwell times. The study we present here focuses on the latter and aims to study the relation between the spread of passengers between the available doors and dwell times on a network-wide level to help understand where it is relevant for interventions to be made.

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The role of environmental requirements in Swedish public procurement of bus transports

Malin Aldenius, Panagiota Tsaxiri, and Helene Lidestam. International Journal of Sustainable Transportation, january 2021
The transport sector needs to become sustainable and public transport has an important role to play. Green public procurement has proven to have great potential to influence the transition to a sustainable public transport sector. Sweden is a good example of a country that uses public procurement in the public transport sector to a large extent and has at the same time come far in the transition to renewable fuel. The aim of this study is to examine what role public transport authorities (PTAs) can have in supporting more environmentally sustainable public transport through public procurement. This was done by a content analysis regarding the expressions of environmental requirements historically, over a ten-year period, in tender documents in Sweden, followed by a workshop where the implications of the findings and future tender processes were discussed with relevant actors. The results showed that all the environmental requirements have become stricter during the studied period, but indicate a tendency for higher use of environmental requirements in tendering of larger areas as well as in tendering of public transport within cities. Specifically, for requirements for fuel, the same tenders also use specific requirements to a higher extent. However, the subsequent workshop discussions indicated that the use of specific requirements is one reason for disagreement among involved actors. Overall, this study of the Swedish public transport case showed that PTAs have a large potential to support more environmentally sustainable solutions using environmental requirements in public procurement.
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Passenger Volumes and Dwell Times for Commuter Trains: A Case Study Using Automatic Passenger Count Data in Stockholm

Ruben Alaric Kuipers and Carl-William Palmqvist. Applied Sciences, June 2022.
This study investigates the relationship between passenger volumes and the frequency and size of dwell times for commuter trains. We use data collected by automatic passenger count systems in Stockholm and show that dwell times often take longer than scheduled. To understand the effect of passenger volumes on delays, we use the frequencies of delays for different passenger volumes and delay sizes. We find that these frequencies differ significantly from a frequency distribution independent of passenger volumes, indicating that passenger volumes have an effect on the frequency of dwell time delays. Neglecting passenger volumes underestimates the frequency of delays in most cases, especially for smaller delays. Although the frequency of dwell time delays increases as passenger volumes increase, the same is not necessarily true for their size. The relationship between passenger volumes and delay sizes is thus non-linear, and it depends on scheduled dwell times. We conclude that small increases in dwell times can result in sharp increases in on-time performance but that only increasing dwell times is not sufficient. Measures to speed up the boarding and alighting process are also necessary.
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The case for ‘public’ transport in the age of automated mobility

Iain Docherty, John Stone, Carey Curtis, Claus Hedegaard Sørensen, Alexander Paulsson, Crystal Legacy & Greg Marsden. Cities, September 2022.

This paper highlights the extent to which a future mobility system dominated by Connected and Autonomous Vehicles (CAVs) poses profound challenges to the ‘publicness’ of the transport and mobility systems of many cities. This is evident at different policy levels: the regulatory posture of governments, changing notions of the contributions of mobility to wider ‘public value’, and the underpinning shared experiences of urban life and citizenship or civitas. There is relatively little discussion of how widespread automation might reduce the ‘publicness’ of transport systems in terms of the range of mobility opportunities they offer, how changing patterns of mobility across neighbourhoods and social groups will contribute to urban restructuring, and the implications of this for public value and the character or civitas of cities. In particular, we note how the huge expansion in mobility choices made possible by CAVs might lead to circumstances in which the outcome of individuals exercising that choice is to change the nature of urban mobility profoundly. We identify a number of key challenges that policy makers will need to address in managing the introduction of CAVs in their cities, and how using the lens of ‘publicness’ might help them do so.

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    Patronage effects of off-peak service improvements in regional public transport

    Joel Hansson, Fredrik Pettersson-Löfstedt, Helena Svensson & Anders Wretstrand. European Transport Research Review. May, 2022.

    The purpose of this study is to look into patronage effects of extended supply outside peak hours on regional public transport services. Previous studies have shown that the service frequency is an attribute of great importance for regional passengers, but little is known about the details regarding peak and off-peak frequencies or service hours. The present study addresses this knowledge gap, departing from the hypothesis that additional off-peak supply means more flexibility for the passengers in terms of departure time options, and possibly also a sense of security for passengers who are uncertain about the time of their (return) trips. Essentially, the added off-peak departures may attract more passengers even if they normally do not or only occasionally use the off-peak services. The patronage effects are explored through four case studies from the region of Scania in southern Sweden. The cases include regional rail and bus services where substantial improvements have been made outside peak hours, resulting in at least hourly all-day services. The results of the study provide new insights into the fundamental planning policy trade-off between maximum frequency and span of public transport services in urban peripheries and rural areas. Importantly, the results suggest that improved time coverage may lead to substantial patronage growth, and this growth is evident also during peak hours, despite unaltered peak hour frequencies. Hence, off-peak departures cannot be assessed only through patronage levels in isolated time periods, let alone on the individual departures.

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    Challenges of delivering TOD in low‑density contexts: the Swedish experience of barriers and enablers

    Robert Hrelja, Lina Olsson, Fredrik Pettersson‑Löfstedt &Tom Rye.European Transport Research Review, 2022.

    Transit Oriented Development (TOD) is key to the success of public transport and for sustainable urban and regional development. Previous research has often focused on delivering TOD in urban areas with high population and building densities. This highlights the need to broaden the scope of TOD approaches to also include less densely populated areas located outside the immediate urban cores as a key concern for policy.

    The aim of this paper is to increase the knowledge of how to deliver TOD in such low-density contexts.

    Three case studies of attempts at delivering TOD in sparsely populated areas in three Swedish city-regions are made. The data for the case studies consist of planning documents and 13 interviews with key stakeholders involved in the planning processes of the three cases.

    The results show that many of the barriers and enablers are rather similar to those identified in research on TOD in much more urban contexts in other parts of the world, but the relationships between them are differently nuanced in low-density contexts. The lack of clear quantified definitions of what TOD is (or is not) allows a more flexible, site-specific understanding of TOD to emerge in this context.

    It is important that a shared vision of TOD in each location is developed by the organizations involved—and such a shared vision appears to be crucial for the development to have a good chance of being delivered. Informal definitions, and individual perceptions (including those of the public) are important; and in locations that are quite “marginal” for TOD, all enablers must interact together positively for the development to have the maximum likelihood of going ahead as planned

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    Being innovative, fun, and green? Hedonic and environmental motivations in the use of green innovations

    Phil Justice Flores & Johan Jansson. Journal of Marketing Management. February 2022.

    This paper seeks to determine the decision-making route relating to hedonic and environmental motivation in green innovation adoption and to show how two similar green innovations can motivate consumers differently. It also aims to determine the effect of domain-specific innovativeness (DSI) on emotions and green identity on environmental motivations. The paper focuses on two types of green transport innovations: shared e-bikes and e-scooters. Four models were tested using structural equation modelling based on survey data from 800 shared e-bike and e-scooter users. The results reveal that the decision to use shared e-bikes follows a cognitive route, while shared e-scooter use follows an affective route. Additionally, findings show that DSI significantly affects positive emotions in the use of both shared microvehicles. However, green identity only impacts the environmental motivations in shared e-bike use.

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    SPICe—Determinants of consumer green innovation adoption across domains: A systematic review of marketing journals and suggestions for a research agenda

    Phil Justice Flores & Johan Jansson. International Journal of Consumer studies. March 2022.

    Over the last decade, the growth in demand for green innovations has become apparent. This can be linked to increased consumer awareness of the environmental problems that the world is facing. This review presents the determinants of consumer green innovation adoption across domains identified in marketing literature. This review's contribution lies in its focus on green innovations or novel products that are promoted as green alternatives to traditional products. Unlike previous studies that aim to determine the motivations of consumers to act green, including recycling, adopting green electricity, choosing public transport over cars, etc., this review outlines the motivations of consumers to adopt green innovations across domains, including organic products, electric powered vehicles, and sustainable household technologies.

    We included and synthesized 47 articles published between 2010 and July 2021 in top marketing journals. After identifying the determinants, we grouped them into four categories: (1) Social, (2) Personal, (3) Innovation, and (4) Contextual and external level determinants, or what we refer to as the SPICe determinants. This categorization is based on the source of the motivation, which is social, individual, innovation-related, or contextual.

    We found a lack of focus on the consumer aspects in green innovation adoption studies, highlighting the need for more research regarding what motivates consumers to adopt these new environmental products.  Furthermore, we showed that no sole determinant could predict green innovation adoption alone. Consequently, we outlined several agendas and questions that future studies could tackle and explore.