| 1. |
- Ait-Ali, Abderrahman, 1991-, et al.
(author)
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The value of additional data for public transport origin-destination matrix estimation
- 2022
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In: Public Transport. - : Springer Science+Business Media B.V.. - 1866-749X .- 1613-7159. ; 14:2, s. 419-439
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Journal article (peer-reviewed)abstract
- Passenger origin–destination data is an important input for public transport planning. In recent years, new data sources have become increasingly common through the use of the automatic collection of entry counts, exit counts and link flows. However, collecting such data can be sometimes costly. The value of additional data collection hence has to be weighed against its costs. We study the value of additional data for estimating time-dependent origin–destination matrices, using a case study from the London Piccadilly underground line. Our focus is on how the precision of the estimated matrix increases when additional data on link flow, destination count and/or average travel distance is added, starting from origin counts only. We concentrate on the precision of the most policy-relevant estimation outputs, namely, link flows and station exit flows. Our results suggest that link flows are harder to estimate than exit flows, and only using entry and exit data is far from enough to estimate link flows with any precision. Information about the average trip distance adds greatly to the estimation precision. The marginal value of additional destination counts decreases only slowly, so a relatively large number of exit station measurement points seem warranted. Link flow data for a subset of links hardly add to the precision, especially if other data have already been added.
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| 2. |
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| 3. |
- Cats, Oded, et al.
(author)
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Optimizing the number and location of time point stops
- 2014
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In: Public Transport. - : Springer Science and Business Media LLC. - 1866-749X .- 1613-7159. ; 6:3, s. 215-235
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Journal article (peer-reviewed)abstract
- Public transport service is subject to multiple sources of uncertainty that impact its reliability. Holding control strategies are a common method to prevent the deterioration of service reliability along the route. This paper expands on previous studies by considering the general case of determining both the optimal number and optimal location of the time point stops (TPS) where holding takes place, and assessing their impacts on transit performance using simulation. Holding times are determined based on a real-time headway-based holding strategy designed to improve service regularity by seeking uniform headways along the route. The evaluation of the performance of alternative TPS layouts is simulation-based, using BusMezzo, a transit operations simulation model which models the dynamic performance of bus transit systems. The proposed framework also considers the multiple objectives incorporating passenger and operator points of view. The simulation-based optimization framework was applied in a case study with one of the premium bus lines in Stockholm, Sweden, using two solution methods—greedy and genetic algorithms. A multi-objective evaluation was conducted considering both passenger and operator perspectives. The results demonstrate that transit performance varies considerably with alternative TPS layouts. The best solution obtained by the proposed methodology reduces total weighted passenger journey times and cycle times compared to both the current layout and the case of no holding control. The proposed method could assist transit agencies and operators in evaluating and recommending alternative time point layouts.
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| 4. |
- Ceccato, Vania, Professor, 1968-, et al.
(author)
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Crime and safety in transit environments : A systematic review of the English and the French literature, 1970-2020
- 2022
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In: Public Transport. - : Springer. - 1866-749X .- 1613-7159. ; 14:1, s. 105-153
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Journal article (peer-reviewed)abstract
- This article reviews five decades of English and French literature on transit safety in several major databases, with the focus on Scopus and ScienceDirect. The review explores the nature and frequency of transit crime and passengers' safety perceptions in transport nodes and along the trip using bibliometric analysis and a systematic review of the literature. The number of retrieved documents was 3137, and 245 were selected for in-depth analysis. Transit safety as a research area took off after the mid-1990s and peaked after the 2010s. The body of research is dominated by the English-language literature (mostly large cities), with a focus on the safety of rail-bound environments and examples of interventions to improve actual and perceived safety for public transportation (PT) users. Highlighting the importance of transit environments along the whole trip, the article also helps advocate for more inclusion of passengers' safety needs and the involvement of multiple stakeholders in implementing PT policies.
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| 5. |
- Dreier, Dennis, et al.
(author)
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Comparison of management strategies for the charging schedule and all-electric operation of a plug-in hybrid-electric bi-articulated bus fleet
- 2020
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In: Public Transport. - : Springer Nature. - 1866-749X .- 1613-7159. ; 12:2, s. 363-404
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Journal article (peer-reviewed)abstract
- This study developed a real-time optimisation (RTO) model that uses real-world bus operation data, i.e. route-specific and time-specific driving cycles. Potentials for energy savings and all-electric operation were estimated for a plug-in hybrid-electric bi-articulated bus fleet (PLUG scenario) that can be managed according to different management strategies. Five strategies A–E were simulated that manage the charging schedule and all-electric operation with different priorities: PLUG-A, prioritise buses for charging by arrival times at the charging station (“first come, first served”); PLUG-B, prioritise buses for charging by energy intensities of the bus routes; PLUG-C, minimise the total energy use of the bus fleet; PLUG-D, maximise the total all-electric time of the bus fleet; and PLUG-E, maximise the total all-electric distance of the bus fleet. For comparison, a business as usual (BAU) scenario with conventional buses and another scenario with hybrid-electric buses (HYB) were simulated. Two weeks of real-world bus operation data from the city of Curitiba in Brazil were used as input data. The study finds that total energy savings of 17% and 27% in the HYB and PLUG scenarios can be achieved compared to the BAU scenario, respectively. Meanwhile, the average shares of the total all-electric time (TAET) and total all-electric distance (TAED) to the total bus fleet operation amount to 20% and 14% in the HYB scenario. Furthermore, both TAET and TAED in the PLUG scenario depend strongly on the chosen strategy amounting to ranges of 21–64% and 17–61%, respectively. Simultaneous maxima were found for strategy D.
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| 6. |
- Hansson, Joel, et al.
(author)
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Effects of rural bus stops on travel time and reliability
- 2021
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In: Public Transport. - : Springer Science and Business Media LLC. - 1613-7159 .- 1866-749X.
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Journal article (peer-reviewed)abstract
- Due to relatively low patronage levels, rural bus stops are sometimes questioned in order to improve travel time and reliability on regional bus services. Previous research into stop spacing has focused on urban areas, which means that there is a lack of knowledge regarding the effects of bus stops in regional networks, with longer distances, higher speeds, and lower passenger volumes, in general. The present study addresses this knowledge gap by analysing the effects of bus stops on a regional bus service regarding average travel times, travel time variability, and on-time performance. This is done by statistical analysis of automatic vehicle location (AVL) data, using a combination of methods previously used for analysis of rail traffic and urban bus operations. The results reveal that bus stops that are only used sporadically have a limited impact on average travel times, in general. In contrast, they are all the more influential on travel time variability, and, in turn, on on-time performance. On the studied bus service, the number of stops made have a far greater impact on travel time variability than any of the other included variables, such as the weather or traffic conditions during peak hours. However, the results suggest that rural bus stops have a much lower impact than what we define as secondary bus stops in urban areas. Consequently, by primarily focusing on bus stop consolidation in urban areas, it is possible to significantly improve service reliability without impairing rural coverage.
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| 7. |
- Häll, Carl Henrik, 1978-, et al.
(author)
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A modeling system for simulation of dial-a-ride services
- 2012
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In: Public Transport. - Berlin / Heidelberg : Springer. - 1866-749X .- 1613-7159. ; 4:1, s. 17-37
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Journal article (peer-reviewed)abstract
- We present a modeling system for simulation of dial-a-ride services. It can be used as a tool for understanding and study how different designs, and different ways to operate a dial-a-ride service, affect the performance and efficiency of the service. The system simulates the operation of a dynamic dial-a-ride service that operates with multiple fleets of vehicles with different capacities, schedules and depots. It can be used to investigate how the setting of service and cost parameters and the design of the service affect the total cost for the operator and level of service for the customer. We describe the different modules in the system and the possible uses of the system. A short simulation study is performed to exemplify how it can be used. In this study the effects of including costs for customer discomfort are evaluated.
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| 8. |
- Häll, Carl Henrik, 1978-, et al.
(author)
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Evaluating the performance of a dial-a-ride service using simulation
- 2015
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In: Public Transport. - : Springer Berlin/Heidelberg. - 1866-749X .- 1613-7159. ; 7:2, s. 139-157
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Journal article (peer-reviewed)abstract
- In this paper we study the effects of changes to a paratransit system operated as a dynamic dial-a-ride service. The scheduling of requests is limited by time window constraints and maximum ride time constraints; costs for customer discomfort in form of waiting time and excess ride time are considered in the planning of the service. The parameters defining these constraints and costs are evaluated based on simulations of a real-world scenario. Several different criteria, both regarding customer level of service and operational costs, are used to evaluate the simulation results. By showing which parameters have a large impact on the different evaluation criteria, we can give guidelines to operators of public transport of how to design their dial-a-ride services. Numerical results are presented and from these results conclusions are drawn regarding which parameters are most important in dynamic dial-a-ride services.
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| 9. |
- Häll, Carl Henrik, 1978-, et al.
(author)
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The Integrated Dial-a-Ride Problem
- 2009
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In: Public Transport. - Berlin / Heidelberg : Springer. - 1866-749X .- 1613-7159. ; 1:1, s. 39-54
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Journal article (peer-reviewed)abstract
- In this paper we present a formulation of the Integrated Dial-a-Ride (IDARP). This problem is to schedule dial-a-ride requests, where some part of each journey may be carried out by a fixed route service. The IDARP is a generalization of the Dial-a-Ride Problem. An arc-based formulation is proposed, and it is shown how the model can be made easier to solve by arc elimination, variable substitution and the introduction of subtour elimination constraints. Small instances of the IDARP can be solved using an exact solution method, and one such instance is studied. We also describe how input and output data can be created and visualized in a geographic information system.
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| 10. |
- Jevinger, Åse, et al.
(author)
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Artificial intelligence for improving public transport : a mapping study
- 2024
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In: Public Transport. - : Springer. - 1866-749X .- 1613-7159. ; 16:1, s. 99-158
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Journal article (peer-reviewed)abstract
- The objective of this study is to provide a better understanding of the potential of using Artificial Intelligence (AI) to improve Public Transport (PT), by reviewing research literature. The selection process resulted in 87 scientific publications constituting a sample of how AI has been applied to improve PT. The review shows that the primary aims of using AI are to improve the service quality or to better understand traveller behaviour. Train and bus are the dominant modes of transport investigated. Furthermore, AI is mainly used for three tasks; the most frequent one is prediction, followed by an estimation of the current state, and resource allocation, including planning and scheduling. Only two studies concern automation; all the others provide different kinds of decision support for travellers, PT operators, PT planners, or municipalities. Most of the reviewed AI solutions require significant amounts of data related to the travellers and the PT system. Machine learning is the most frequently used AI technology, with some studies applying reasoning or heuristic search techniques. We conclude that there still remains a great potential of using AI to improve PT waiting to be explored, but that there are also some challenges that need to be considered. They are often related to data, e.g., that large datasets of high quality are needed, that substantial resources and time are needed to pre-process the data, or that the data compromise personal privacy. Further research is needed about how to handle these issues efficiently.
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| 11. |
- Jevinger, Åse, et al.
(author)
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Exploring the potential of using real-time traveler data in public transport disturbance management
- 2019
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In: Public Transport. - : Springer. - 1866-749X .- 1613-7159. ; 11:2, s. 413-441
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Journal article (peer-reviewed)abstract
- New and emerging technologies, such as connected sensors, smartphones and smart cards, offer new possibilities to collect rich real-time information about travelers. Moreover, smartphones also enable travelers to actively share information, for instance, about their intended travel plans. This type of information can be used to improve public transport disturbance management. In this paper, the potential gain of collecting different types of information about travelers is explored to support action decisions made by public transport actors, during unplanned disturbances. Based on interviews and workshops, the paper provides a mapping between different information types and possible action decisions that can be supported. Furthermore, based on a literature review focused on current and potential technical solutions, a guidance to which solutions support which type of action decisions, is also provided. Amongst others, the results show that automated fare collection, which is one of the most commonly implemented systems providing real-time information about the traveler, can support a large number of action decisions relevant in unplanned disturbance scenarios. The technical solution providing the most extensive information, and thereby providing the best support for the action decisions, involves smartphone apps delivering user-generated information. The drawback with this solution is that it might violate privacy, and that it typically relies on the travelers providing relevant information voluntarily.
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| 12. |
- Johansson, Fredrik, et al.
(author)
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Local performance measures of pedestrian traffic
- 2014
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In: Public Transport. - : Springer Science and Business Media LLC. - 1866-749X .- 1613-7159. ; 6:1-2, s. 159-183
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Journal article (peer-reviewed)abstract
- Efficient interchange stations, where travelers are changing lines and/or travel modes, are essential for the functionality of the whole public transport system. By studying pedestrian movements, the level of service and effectiveness imposed by the design of the interchange station can be evaluated. We address the problem by microsimulation, where a social force model is used for the phenomenological description of pedestrian interactions. The contribution of this paper is the proposal of measures describing the density, delay, acceleration and discomfort for pedestrian flows. Simulation experiments are performed for the movements in two canonical pedestrian areas, a corridor and a corridor intersection. Clearly, each of the four measures gives a description for how pedestrians impede each other, and hence for the efficiency at the facility. There is, however, different information provided by each measure, and we conclude that they all are well-motivated for quantifying the level of service in a pedestrian flow. We also illustrate the outcome for a railway platform, with two trains arriving in parallel.
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| 13. |
- Kecman, Pavle, 1982-, et al.
(author)
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Predictive modelling of running and dwell times in railway traffic
- 2015
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In: Public Transport. - : Springer Berlin/Heidelberg. - 1866-749X .- 1613-7159. ; 7:3, s. 295-319
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Journal article (peer-reviewed)abstract
- Accurate estimation of running and dwell times is important for all levels of planning and control of railway traffic. The availability of historical track occupation data with a high degree of granularity inspired a data-driven approach for estimating these process times. In this paper we present and compare the accuracy of several approaches to model running and dwell times in railway traffic. Three global predictive model approaches are presented based on advanced statistical learning techniques: LTS robust linear regression, regression trees and random forests. Also local models are presented for a particular train line, station or block section, based on LTS robust linear regression with some refinements. The models are validated and compared using a test set independent from the training set. The applicability of the proposed data-driven approach for real-time applications is proved by the accuracy of the obtained estimates and the low computation times. Overall, the local models perform best both in accuracy and computation time.
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| 14. |
- Lidén, Tomas, 1961-
(author)
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Coordinating maintenance windows and train traffic : a case study
- 2020
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In: Public Transport. - : Springer. - 1866-749X .- 1613-7159. ; 12:2, s. 261-298
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Journal article (peer-reviewed)abstract
- This paper concerns a case study for optimal planning and coordination of railway maintenance windows and train traffic. The purpose is to validate a previously presented optimization model on a demanding real-life problem instance and to obtain results that apply in similar planning situations. A mixed integer linear programming model is used for a 913 km long, single-track railway line through the northern part of Sweden, with traffic consisting of 82 trains per day, most of which are freight trains. Cyclic 1-day schedules are produced, which show that 2 h long maintenance windows can be scheduled with small adjustments of the train traffic. The sensitivity for cost changes is studied, which shows that the train costs must increase by more than 30% in order to change the structure of the window solutions. Resource efficient window schedules are obtained by assigning maintenance teams to all windows while respecting crew work and rest time restrictions. A comparison with manually constructed plans from the Swedish Transport Administration indicates that larger window volumes can be scheduled at a lower cost and with solution structures which are deemed reasonable and useful as guidance for constructing the real window patterns. Finally, we estimate that using an integrated planning approach (where maintenance and trains are jointly planned) instead of a sequential approach (where a train timetable has precedence over the maintenance windows), will give maintenance cost savings of 11–17%, without incurring any large cost increases for the train traffic. The paper also presents a method for achieving cyclic schedules without any period-deciding variables, and discusses the consequences of the aggregated capacity usage model that has been adopted.
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| 15. |
- Ljunggren, Fredrik, et al.
(author)
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Railway timetabling : a maximum bottleneck path algorithm for finding an additional train path
- 2021
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In: Public Transport. - : Springer. - 1866-749X .- 1613-7159. ; 13, s. 597-623
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Journal article (peer-reviewed)abstract
- We present an algorithm to insert a train path in an existing railway timetable close to operation, when we want to affect the existing (passenger) traffic as little as possible. Thus, we consider all other trains as fixed, and aim for a resulting train path that maximizes the bottleneck robustness, that is, a train path that maximizes the temporal distance to neighboring trains in the timetable. Our algorithm is based on a graph formulation of the problem and uses a variant of Dijkstra’s algorithm. We present an extensive experimental evaluation of our algorithm for the Swedish railway stretch from Malmö to Hallsberg. Moreover, we analyze the size of our constructed graph.
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| 16. |
- Posada, Marcus, et al.
(author)
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The integrated dial-a-ride problem with timetabled fixed route service
- 2017
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In: Public Transport. - : Springer. - 1866-749X .- 1613-7159. ; 9:1-2, s. 217-241
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Journal article (peer-reviewed)abstract
- This paper concerns operational planning of door-to-door transportation systems for the elderly and/or disabled, who often need a more flexible transportation system than the rest of the population. Highly flexible, but very costly direct transportation is often offered as a complement to standard fixed route public transport service. In the integrated dial-a-ride problem (IDARP), these modes of transport are combined and certain legs of the passengers journeys may be performed with the fixed route public transport system. We extend the IDARP and include timetables for the fixed route services, forcing the fleet of vehicles to schedule the arrival at transfer locations with care. Two mixed integer linear programming formulations of the integrated dial-a-ride problem with timetables are presented and analyzed. The key modeling challenge is that of the transfers between the fleet of vehicles and the fixed route public transport system. The formulations differ in how the transfers are modeled and the differences are thoroughly discussed. The computational study compares the formulations in terms of network size, computational time and memory usage and conclusions about their performances are drawn.
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| 17. |
- Raposo, Hugo, et al.
(author)
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Dimensioning reserve bus fleet using life cycle cost models and condition based/predictive maintenance: a case study
- 2018
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In: Public Transport. - : Springer. - 1866-749X .- 1613-7159. ; 10:1, s. 169-190
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Journal article (peer-reviewed)abstract
- The paper demonstrates the dependence of a fleet reserve of buses on the maintenance policy of the whole fleet, in particular, condition-based maintenance using a motor oil degradation analysis. The paper discusses an approach to evaluate the oil degradation and the prediction of the next value for one relevant oil variable. The methodology to evaluate the reserve fleet is based on bus availability, estimated through the mean time between failures and the mean time to repair ratios. Through the use of econometric models, it is possible to determine the most rational size of the reserve fleet.
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| 18. |
- Rydergren, Clas, 1972-
(author)
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Comparison of headway-based public transport models : Numerical experiments for Stockholm
- 2013
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In: Public Transport. - : Springer Berlin/Heidelberg. - 1866-749X .- 1613-7159. ; 5:3, s. 177-191
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Journal article (peer-reviewed)abstract
- In this paper we evaluate the output from four headway-based public transport model variants for modeling the public transports in Stockholm, Sweden. The results from the four models are analyzed and compared to trip observations. The comparisons are based on model instances where the parameters in the generalized travel time function are calibrated. The best possible parameter values have been found using the calibration procedures SPSA and Compass search. Two different objective functions have been evaluated for the calibration.Numerical experiments have been performed using a public transport model implemented in Visum by Storstockholms lokaltrafik. For the calibration and analysis, trip observations from the Swedish national travel survey and data generated from a public transport trip planner are used.From the numerical results, it is concluded that it is of less importance to find the best possible parameter values in the generalized cost function than selecting the best model variant. For the Stockholm public transport model, the numerical results indicate that the models in the class of Random departure time models result in a better fit to the observed trips than the models in the class of Optimal strategies.
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| 19. |
- Zhang, Yizhou, et al.
(author)
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Impact of real-time crowding information : A Stockholm metro case study
- 2017
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In: Public Transport. - : Springer. - 1866-749X .- 1613-7159. ; 9:3, s. 483-499
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Journal article (peer-reviewed)abstract
- The paper evaluates the impact of real-time crowding information (RTCI) provision based on a pilot study at a Stockholm metro station. During a 6-day test period, RTCI for each car in the next arriving train was provided through a visual display and speakers. The impact is evaluated in three dimensions: (1) passenger attention is analyzed using video analysis; (2) passenger valuation is evaluated with traveler surveys; (3) passenger action is analyzed with in-vehicle passenger load data. It is estimated that around 25% of the passengers noticed, understood and considered the provided information useful for their travel decisions. Further, RTCI had a statistically significant positive impact on the boarding distribution between cars and, as a result, on the downstream in-vehicle crowding in the trains. RTCI reduced the share of passengers boarding the first, most crowded car by 4.3% points for trains that were crowded on arrival, and increased the share of passengers boarding the second, less crowded car by 4.1% points. The findings also suggest that many passengers may value the provided crowding information positively even though it does not change their travel decisions. The results indicate that RTCI may be a useful technology for public transport operators and agencies for increasing the utilization of available train capacity and reducing crowding.
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| 20. |
- Berggren, Ulrik, et al.
(author)
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Effects from usage of pre‑trip information and passenger scheduling strategies on waiting times in public transport: An empirical survey based on a dedicated smartphone application
-
In: Public Transport. - 1613-7159. ; :Special Issue CASPT
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Journal article (peer-reviewed)abstract
- Waiting times are important indicators of the degree of travel time optimisation andother behavioural traits among public transport (PT) passengers. As previous studieshave shown, the level and usage of pre-trip information regarding schedule or realtime departures are important factors that infuence the potential to realise traveltime savings by enabling PT passengers to optimise waiting times. Most empiricalevidence regarding the revealed PT travel behaviour concerning information levelsis based on manual interviews or traditional travel surveys, in which there is a riskthat the actual context of where and when the choice of departure time was madeis not taken into account. This paper reports the results of a travel survey based ona dedicated smartphone application applied in a feld study in a Swedish mid-sizeurban and regional context. Context-aware notifcation prompting was used to allowrespondents to state their use of pre-trip information as well as whether they hadpre-planned their trip and how contingent planning aids were used for time optimisation. The implications on passenger waiting times of the use of informationregarding departure times by passengers were emphasised during analyses of theresulting data, along with personal characteristics, in which auxiliary sources suchas timetable data and Automatic Vehicle Location were utilised to determine groundtruth trip trajectories and trip-contextual factors. The results indicate the signifcance of having access to pre-trip information, especially for long trips above onehour’s duration, in order to pre-plan and thereby optimise waiting times. In addition,the use and source of pre-trip information difer among age and gender groups. Trippurpose and time of day to some extent determine waiting times and choice of tripoptimisation strategy (arrival or departure time).
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| 21. |
- Ivina, Daria, et al.
(author)
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Uncertainties in scheduling and execution of trackwork in Sweden
- 2023
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In: Public Transport. - 1613-7159. ; 15, s. 767-789
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Journal article (peer-reviewed)abstract
- Trackwork planning and scheduling are demanding because they require strategic foresight and must be completed well in advance. In Sweden, trackwork is performed by maintenance contracting companies during an operation period free from trains. In the contractors’ practice, once the maintenance plan is authorised, some unexpected events might interrupt the plan’s execution, leading to uncertainties. The purpose of this study is to identify and classify uncertainties and strategies applied to manage uncertainties in the contractors’ everyday planning and scheduling of trackwork. This work presents semi-structured interviews with foremen and planners at railway maintenance contracting companies in Sweden. The main findings show that in trackwork planning and scheduling, contractors deal with two types of uncertainties: internal and external. We categorised uncertainties and strategies to deal with uncertainties and described them on tactical and operational levels. The majority of the revealed uncertainties led to trackwork rescheduling. Furthermore, we suggest that current strategies to manage uncertainties applied at contracting companies can be improved by revising organisational design strategies for maintenance projects. This work increases the understanding and supports the management of uncertainties in trackwork planning and scheduling.
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