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Hatzenbühler, JonasORCID iD iconorcid.org/0000-0001-9447-2823
Publications (10 of 15) Show all publications
Hatzenbühler, J., Jenelius, E., Gidofalvi, G. & Cats, O. (2024). Multi-purpose pickup and delivery problem for combined passenger and freight transport. Transportation
Open this publication in new window or tab >>Multi-purpose pickup and delivery problem for combined passenger and freight transport
2024 (English)In: Transportation, ISSN 0049-4488, E-ISSN 1572-9435Article in journal (Refereed) Published
Abstract [en]

Recent advances in the development of modular transport vehicles allow deploying multi-purpose vehicles, which enable alternate transport of different demand types. In this study, we propose a novel variant of the pickup and delivery problem, the multi-purpose pickup and delivery problem, where multi-purpose vehicles are assigned to serve a multi-commodity flow. We solve a series of use case scenarios using an exact optimization algorithm and an adaptive large neighborhood search algorithm. We compare the performance of a multi-purpose vehicle fleet to a mixed fleet of single-purpose vehicles. Depending on cost parameters, our findings suggest that in certain scenarios, the total costs can be reduced by an average of 13% when multi-purpose vehicles are deployed, while at the same time reducing total vehicle trip duration and total distance traveled by on average 33% and 16%, respectively. The required fleet size can be reduced by 35% on average when operating multi-purpose vehicles. The results can be used by practitioners and policymakers to determine if the combined service of passenger and freight demand flows with multi-purpose vehicles in a given system will yield benefits compared to existing transport operations.

National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-347032 (URN)10.1007/s11116-024-10482-9 (DOI)
Funder
Vinnova, 2020-00565
Available from: 2024-05-28 Created: 2024-05-28 Last updated: 2024-05-28
Hatzenbühler, J., Jenelius, E., Gidofalvi, G. & Cats, O. (2023). Modular vehicle routing for combined passenger and freight transport. Transportation Research Part A: Policy and Practice, 173, 103688-103688, Article ID 103688.
Open this publication in new window or tab >>Modular vehicle routing for combined passenger and freight transport
2023 (English)In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 173, p. 103688-103688, article id 103688Article in journal (Refereed) Published
Abstract [en]

This study investigates the potential of modular vehicle concepts and consolidation to increasethe efficiency of urban freight and passenger transport. Modularity is achieved by connectingmultiple vehicles together to form a platoon. Consolidation is realized by integrating passengerand freight demand in the routing problem. Vehicles are specific for each demand type but canbe connected freely, allowing the transport of multiple demand types in the same platoon. Therouting problem formulation considers travel time costs, travel distance costs, fleet size costs,and unserved requests costs. The operations are modeled in a novel modular multi-purposepickup and delivery problem (MMP-PDP) which is solved using CPLEX and Adaptive LargeNeighborhood Search (ALNS). In an extensive scenario study, the potential of the modularvehicle type is explored for different spatial and temporal demand distributions. A parameterstudy on vehicle capacity, vehicle range and platoon cost saving is performed to assess theirinfluence on efficiency. The experiments indicate a cost saving of 48% due to modularity and anadditional 9% due to consolidation. The reduction mainly stems from reduced operating costsand reduced trip duration, while the same number of requests can be served in all cases. Emptyvehicle kilometers are reduced by more than 60% by consolidation and modularity. A large-scalecase study in Stockholm highlights the practical applicability of the modular transport system.The proposed model and optimization framework can be used by companies and policy makersto identify required fleet sizes, optimal vehicle routes and cost savings due to different typesof operation and vehicle technology

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Public transportation, Freight transportation, Modular vehicles, Heuristic optimization
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-328193 (URN)10.1016/j.tra.2023.103688 (DOI)001053303900001 ()2-s2.0-85154022246 (Scopus ID)
Funder
Integrated Transport Research Lab (ITRL)Vinnova, 2020-00565Swedish National Infrastructure for Computing (SNIC)
Note

QC 20230608

Available from: 2023-06-05 Created: 2023-06-05 Last updated: 2023-09-21Bibliographically approved
Hatzenbühler, J., Jenelius, E., Gidofalvi, G. & Cats, O. (2022). Multi-purpose vehicle assignment for combined passenger and freight transport. In: : . Paper presented at Transportation Research Board (TRB) 101st Annual Meeting.
Open this publication in new window or tab >>Multi-purpose vehicle assignment for combined passenger and freight transport
2022 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Recent advances in the development of modular transport vehicles allow deploying multi-purpose vehicles, which enable alternate transport of different demand types. In this study, we propose a novel variant of the pickup and delivery problem, the multi-purpose pickup and delivery problem, where multi-purpose vehicles are assigned to serve a multi-commodity flow. We solve a series of use case scenarios using an exact optimization algorithm and an adaptive large neighborhood search algorithm. We compare the performance of a multi-purpose vehicle fleet to a mixed fleet of single-purpose vehicles. Our findings suggest that total costs can be reduced by an average of 13% when multi-purpose vehicles are deployed, while at the same time reducing total vehicle trip duration and total distance travelled by on average 33% and 16%, respectively. The required fleet size can be reduced by 35% on average when operating multi-purpose vehicles. The results can be used by practitioners and policymakers to determine if the combined service of passenger and freight demand flows with multi-purpose vehicles in a given system will yield benefits compared to existing transport operations.

Keywords
Public transportation, Freight transportation, Multi-purpose vehicles, Heuristic optimization
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-333683 (URN)
Conference
Transportation Research Board (TRB) 101st Annual Meeting
Funder
Vinnova, 2020-00565Swedish National Infrastructure for Computing (SNIC)
Note

QC 20230809

Available from: 2023-08-09 Created: 2023-08-09 Last updated: 2023-08-09Bibliographically approved
Hatzenbühler, J., Cats, O. & Jenelius, E. (2022). Network design for line-based autonomous bus services. Transportation, 49(2), 467-502
Open this publication in new window or tab >>Network design for line-based autonomous bus services
2022 (English)In: Transportation, ISSN 0049-4488, E-ISSN 1572-9435, Vol. 49, no 2, p. 467-502Article in journal (Refereed) Published
Abstract [en]

The maturing of autonomous driving technology in recent years has led to several pilot projects and the initial integration of autonomous pods and buses into the public transport (PT) system. An emerging field of interest is the design of public transport networks operating autonomous buses and the potential to attract higher levels of travel demand. In this work a multi-objective optimization and multi-agent simulation framework is developed to study potential changes in the network design and frequency settings compared to conventional PT systems when autonomous vehicles (AV) systems are deployed on fixed-route networks. During the optimization process multiple deployment scenarios (network configurations and service frequency) are evaluated and optimized considering the operator cost, user cost and infrastructure preparation costs of the system. User-focused network design and operator-focused network design are studied for a real-world urban area in Sweden. The results provide insights into the network design and level of service implications brought about by the deployment of autonomous bus (AB) when those are integrated in route-based PT systems. We show that the deployment of autonomous buses result with a network design that increases service ridership. In the context of our case study this increase is likely to primarily substitute walking.

Place, publisher, year, edition, pages
Springer Nature, 2022
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-292901 (URN)10.1007/s11116-021-10183-7 (DOI)000628070400001 ()2-s2.0-85102500377 (Scopus ID)
Funder
Integrated Transport Research Lab (ITRL)Vinnova
Note

QC 20221025

Available from: 2021-04-15 Created: 2021-04-15 Last updated: 2023-10-09Bibliographically approved
Chen, H., Hatzenbühler, J. & Jenelius, E. (2022). Pick-Up and Delivery Problem for Sequentially Consolidated Urban Transportation with Mixed and Multi-Pupropse Vehicle Fleet. Journal of Advanced Transportation, 2022, Article ID 2920532.
Open this publication in new window or tab >>Pick-Up and Delivery Problem for Sequentially Consolidated Urban Transportation with Mixed and Multi-Pupropse Vehicle Fleet
2022 (English)In: Journal of Advanced Transportation, ISSN 0197-6729, E-ISSN 2042-3195, Vol. 2022, article id 2920532Article in journal (Refereed) Published
Abstract [en]

Different urban transportation flows (e.g., passenger journeys, freight distribution, and waste management) are conventionally separately handled by corresponding single-purpose vehicles (SVs). The multi-purpose vehicle (MV) is a novel vehicle concept that can enable the sequential sharing of different transportation flows by changing the so-called modules, thus theoretically improving the efficiency of urban transportation through the utilization of higher vehicles. In this study, a variant of the pick-up and delivery problem with time windows is established to describe the sequential sharing problem considering both MVs and SVs with features of multiple depots, partial recharging strategies, and fleet sizing. MVs can change their load modules to carry all item types that can also be carried by SVs. To solve the routing problem, an adaptive large neighborhood search (ALNS) algorithm is developed with new problem-specific heuristics. The proposed ALNS is tested on 15 small-size cases and evaluated using a commercial MIP solver. Results show that the proposed algorithm is time-efficient and able to generate robust and high-quality solutions. We investigate the performance of the ALNS algorithm by analyzing convergence and selection probabilities of the heuristic solution that destroy and repair operators. On 15 large-size instances, we compare results for pure SV, pure MV, and mixed fleets, showing that the introduction of MVs can allow smaller fleet sizes while approximately keeping the same total travel distance as for pure SVs.

Place, publisher, year, edition, pages
Hindawi Limited, 2022
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-310768 (URN)10.1155/2022/2920532 (DOI)000773704600004 ()2-s2.0-85127097555 (Scopus ID)
Note

QC 20220407

Available from: 2022-04-07 Created: 2022-04-07 Last updated: 2022-06-25Bibliographically approved
Hatzenbühler, J. (2022). Simulation and optimization of innovative urban transportation systems. (Doctoral dissertation). Stockholm, Sweden: KTH Royal Institute of Technology
Open this publication in new window or tab >>Simulation and optimization of innovative urban transportation systems
2022 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The ongoing trends of urbanization and e-commerce continuously challenge the existing urban transportation systems. A steadily growing number of people traveling within urban areas, results in more trips taken with public transportation systems. Additionally, the constantly increasing number of urban logistic operations leads to more commercial vehicles in cities. These ongoing trends and the need for more sustainable operations require the design of robust and efficient transportation systems which additionally provide a high level of service for their users. In recent years, two innovative approaches have been proposed to overcome these challenges. That is, first, the use of autonomous buses as a replacement, or an addition to existing public transportation systems, and second, the consideration of consolidating multiple types of demand (i.e. passenger and freight) when planning and designing transportation systems. In this thesis, both approaches are studied and their impact on urban transportation systems is evaluated. This is achieved by developing novel simulation-based optimization models that consider technology-specific cost structures and capture the changed mode of operation for different vehicle technologies.

In Papers I and II the deployment of autonomous buses on fixed-line public transportation networks is investigated. Changes in service frequency, vehicle capacity, and metrics corresponding to the level of service for public transportation users due to new vehicle technology are investigated. Furthermore, Paper I explores the transition from conventional public transportation systems to systems operated by autonomous buses, while Paper II investigates the changes in network design due to autonomous bus operations. The developed models are applied to case studies in Kista, Sweden, and Barkarby, Sweden. Two key results can be identified in these studies. First, autonomous bus deployment leads to an increase in service frequency, while waiting time for passengers can be reduced. Second, more passengers are attracted to autonomous bus lines by reducing the access walking distances and increased level-of-service. On more complex networks these trends are amplified. 

In each of Papers III and IV, a novel pickup and delivery model is proposed. The models consider vehicle concepts which allow for the consolidated transport of multiple demand types. In Paper III the vehicles can serve different types of demand by exchanging purpose-specific modules at dedicated service depots, while in Paper IV individual demand-specific vehicles can form platoons with modular length and varying configuration. The results of the extensive scenario studies and parameter analysis show that for multi-purpose vehicle operations (Paper III) the total costs can be reduced by an average of 13% and for platoon operations (Paper IV) the total costs are reduced by over 48%. In both models, the cost savings stem mainly from a reduction in fleet size, total vehicle trip duration, and the total distance traveled.

Abstract [sv]

De pågående trenderna med urbanisering och e-handel utmanar kontinuerligt de befintliga stadstransportsystemen. Ett stadigt växande antal människor som reser inom tätorter leder till fler resor med kollektivtrafik (PT). Dessutom leder det ständigt ökande antalet urbana logistikverksamheter till fler kommersiella fordon i städerna. Dessa pågående trender och behovet av mer hållbar verksamhet kräver design av robusta och effektiva transportsystem som dessutom ger en hög servicenivå för sina användare. Under de senaste åren har två innovativa tillvägagångssätt föreslagits för att övervinna dessa utmaningar. Det vill säga, för det första, användningen av autonoma bussar (AB) som en ersättning, eller ett tillägg till befintliga PT-system, och för det andra, övervägandet av att konsolidera flera typer av efterfrågan (dvs. passagerare och gods) vid planering och utformning av transportsystem. I denna avhandling studeras båda tillvägagångssätten och deras inverkan på stadstransportsystem utvärderas. Detta uppnås genom att utveckla nya simuleringsbaserade optimeringsmodeller som tar hänsyn till teknikspecifika kostnadsstrukturer och fångar det förändrade driftsättet för olika fordonsteknologier.

I Paper I och II undersöks utbyggnaden av AB på fasta PT-nät. Förändringar i servicefrekvens, fordonskapacitet och mått som motsvarar servicenivån för PT-användare på grund av ny fordonsteknik undersöks. Vidare undersöker Paper I den sekventiella  övergången från konventionella PT-system till system som drivs av AB, medan Paper II undersöker förändringarna i nätverksdesign på grund av AB-drift. De utvecklade modellerna tillämpas på fallstudier i Kista, Sverige och Barkarby, Sverige. Två nyckelresultat kan identifieras i dessa studier. För det första leder AB-insatsen till en ökad servicefrekvens, samtidigt som väntetiden för passagerarna kan minskas. För det andra lockas fler passagerare till linjer med AB genom att gångavstånden minskas och servicenivån ökas. På mer komplexa nätverk förstärks dessa trender.

I vart och ett av dokumenten III och IV föreslås en ny modell för hämtning och leverans. Modellerna tar hänsyn till fordonskoncept som möjliggör konsoliderad transport för olika typer av efterfrågan. I Paper III kan fordonen betjäna olika typer av efterfrågan genom att byta ut ändamålsspecifika moduler på dedikerade servicedepåer, medan i Paper IV kan individuella behovsspecifika fordon bilda plutoner med modullängd och varierande konfiguration. Resultaten av de omfattande scenariestudierna och parameteranalysen visar att för multi-purpose vehicle operations (Paper III) kan de totala kostnaderna minskas med i genomsnitt 13% och för pluton operationer (Paper IV) de totala kostnaderna minskas med över 48%. I båda modellerna härrör kostnadsbesparingarna huvudsakligen från en minskning av flottans storlek, totala fordonsresan och den totala tillryggalagda sträckan.

Place, publisher, year, edition, pages
Stockholm, Sweden: KTH Royal Institute of Technology, 2022. p. 46
Series
TRITA-ABE-DLT ; 2225
National Category
Transport Systems and Logistics
Research subject
Transport Science, Transport Systems
Identifiers
urn:nbn:se:kth:diva-311840 (URN)978-91-8040-256-9 (ISBN)
Public defence
2022-06-14, Kollegiesalen, Brinellvägen 8, KTH Campus, videolänk https://kth-se.zoom.us/j/65778805858, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20220518

Available from: 2022-05-18 Created: 2022-05-16 Last updated: 2022-06-25Bibliographically approved
Hatzenbühler, J. (2020). Transition Towards Fixed-Line Autonomous Bus Transportation Systems. (Licentiate dissertation). Stockholm: KTH Royal Institute of Technology
Open this publication in new window or tab >>Transition Towards Fixed-Line Autonomous Bus Transportation Systems
2020 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

In the last years the steady development of autonomous driving technology has enabled the deployment of more mature autonomous vehicles. These vehicles have been applied in several pilot projects worldwide, most commonly in the form of small buses. At the same time, the amount of people traveling in especially urban areas is continuously growing, resulting in more trips in the transportation system. An efficient transportation system is therefore required to serve the growing passenger demand. Autonomous buses (AB) are assumed to have lower operational costs and with that public transport (PT) systems can potentially be designed more efficiently to facilitate the increased demand better. In this study, an AB specific simulation-based optimization framework is proposed which allows analyzing the impacts AB have on line-based PT systems. The thesis focuses on the transition from existing PT systems towards line-based PT systems operated partially or exclusively by AB.

Existing work on PT service design is extended so that realistic AB systems can be investigated. This is achieved by (i) using AB specific operator cost formulations, (ii) integrating infrastructure costs required for AB operations, (iii) utilizing a dynamic, stochastic and schedule-based passenger assignment model for the simulation of PT networks and by (iv) formulating a multi-objective optimization problem allowing to investigate the stakeholder-specific impacts of AB.

In Paper I the effects of AB, concerning service frequency and vehicle capacity, on fixed-line PT networks are investigated. Among other metrics, the changes are evaluated based on differences in level of service and passenger flow. Additionally, the sequential introduction of AB in existing PT systems is studied. The framework addresses a case study in Kista, Sweden. The study confirmed the initial hypothesis that the deployment of AB leads to an increase in service frequency and a marginal reduction in vehicle capacity. Furthermore, it could be seen that the deployment of AB increases the passenger load on AB lines and that passengers can shift from other PT modes towards the AB services.

Paper II incorporates a multi-objective heuristic optimization algorithm in the simulation framework. The study investigates changes in transport network design based on the deployment of AB. The differences in user-focused and operator-focused network design are analyzed and the impact of AB on these is quantified. This study is applied to a case study in Barkarby, Sweden where a full-sized, line-based PT network is designed to exclusively operate AB. Among other findings, we show that the autonomous technology reduces the number of served bus stops and reduces the total PT network size. Additionally, average passenger waiting time can be reduced when deploying AB on user-focused PT networks, which in turn leads to a further reduction of user cost.

Abstract [sv]

De senaste årens framsteg inom autonom körteknik har lett till mer mogna autonoma fordon. Dessa fordon har setts tillämpas i flera pilotprojekt över hela världen, oftast i form av små bussar. Samtidigt växer mängden människor som reser, särskilt i stadsområden, kontinuerligt vilket resulterar i fler resor i transportsystemet. Därför krävs ett effektivt transportsystem för att tillgodose det växande antalet passagerare. Autonoma bussar (AB) antas ha lägre driftskostnader och därmed kan system för kollektivtrafik (public transport, PT) potentiellt utformas mer effektivt för att underlätta den ökade efterfrågan bättre. I denna studie föreslås ett AB-specifikt simuleringsbaserat optimeringsramverk som gör det möjligt att analysera effekterna AB har på linjebaserade PT-system. Avhandlingen fokuserar på övergången från befintliga PT-system till linjebaserade PT-system som delvis eller uteslutande drivs av AB.

Befintligt arbete med PT-tjänstdesign utvidgas så att realistiska AB-system kan undersökas. Detta uppnås genom att (i) använda AB-specifika operatörskostnadsformuleringar, (ii) integrera infrastrukturkostnader som krävs för AB-verksamhet, (iii) använda en dynamisk, stokastisk och schemabaserad modell för att tilldela passagerare vid simulering av PT-nät samt genom att (iv) formulera ett multifunktionellt optimeringsproblem som gör det möjligt att undersöka AB: s intressespecifika effekter.

I artikel I undersöks effekterna av AB, med avseende på servicefrekvens och fordonskapacitet, på fasta linjer i PT-nät. Förändringar utvärderas bland annat utifrån skillnader i servicenivå och passagerarflöde. Dessutom studeras den sekventiella introduktionen av AB i befintliga PT-system. Det föreslagna ramverket tillämpas på en fallstudie i Kista, Sverige. Studien bekräftade den initiala hypotesen att utplaceringen av AB leder till en ökning av servicefrekvensen och en marginell minskning av fordonens kapacitet. Vidare kunde man se att utplaceringen av AB ökar passagerarbelastningen på AB-linjer och att passagerare kan skifta från andra PT-former mot AB-tjänsterna.

Artikel II integrerar en multifunktionell heuristisk optimeringsalgoritm i ramverket för simuleringen. Studien undersöker förändringar i transportnätverkets design baserat på implementeringen av AB. Skillnaderna i användarfokuserad och operatörsfokuserad nätverksdesign analyseras och AB: s inverkan på dessa kvantifieras. Denna studie tillämpas på en fallstudie i Barkarby, Sverige, där ett fullstort linjebaserat PT-nät är utformat för att exklusivt driva AB. Vi visar bland annat att den autonoma tekniken reducerar antalet använda busshållplatser och reducerar den totala PT-nätstorleken. Dessutom kan implementeringen av AB på användarfokuserade PT-nät ytterligare förbättra servicenivån främst genom att minska den genomsnittliga väntetiden per passagerare.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2020. p. 23
Series
TRITA-ABE-DLT ; 2011
Keywords
Autonomous Buses, Public Transportation, Network Design, Resource Allocation, Simulation-based multi-objective Optimization
National Category
Transport Systems and Logistics
Research subject
Transport Science
Identifiers
urn:nbn:se:kth:diva-272008 (URN)978-91-7873-514-3 (ISBN)
Presentation
2020-05-25, https://kth-se.zoom.us/j/543209993, Du som saknar dator/datorvana kan kontakta jenelius@kth.se för information"., 10:00 (English)
Opponent
Supervisors
Available from: 2020-04-29 Created: 2020-04-15 Last updated: 2022-06-26Bibliographically approved
Hatzenbühler, J., Cats, O. & Jenelius, E. (2020). Transitioning towards the deployment of line-based autonomous buses: Consequences for service frequency and vehicle capacity. Transportation Research Part A: Policy and Practice, 138, 491-507
Open this publication in new window or tab >>Transitioning towards the deployment of line-based autonomous buses: Consequences for service frequency and vehicle capacity
2020 (English)In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 138, p. 491-507Article in journal (Refereed) Published
Abstract [en]

The deployment of autonomous buses (AB) is expected to have consequences for service design facilitated by its cost function structure. We study the impacts of AB deployment in line-based public transport (PT) systems. In particular, we examine the transition phase where AB is sequentially deployed, involving the selection of lines for which AB will be introduced. To this end, we develop a modeling framework using a dynamic public transportation assignment and operations simulation model that captures users' adaptive path choices. An analytical model is used to determine the initial solutions in terms of service frequency and vehicle capacity for the simulation framework. Due to their different cost function structures, the deployment of AB may be accompanied by changes in the service frequency and vehicle capacity settings and consequently also on passenger flow distribution across the network. Both the simultaneous and the sequential deployment of AB on multiple lines are investigated. Deployment solutions are assessed in terms of the both total operator and user cost. The decision variables are vehicle capacity per line, service frequency per line and vehicle technology per line - i.e. either manually driven or fully automated buses. The framework is applied to a case study in Kista, Stockholm. The study shows that AB service have the potential to attract passengers through improved service provision. A sensitivity analysis is carried out concerning the effects of different cost parameters and demand levels on the deployment of AB in fixed line operations.

Place, publisher, year, edition, pages
Elsevier BV, 2020
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-272001 (URN)10.1016/j.tra.2020.06.019 (DOI)000553351200029 ()2-s2.0-85087711282 (Scopus ID)
Note

QC 20200909

Available from: 2020-04-15 Created: 2020-04-15 Last updated: 2022-06-26Bibliographically approved
Hatzenbühler, J., Jenelius, E. & Cats, O. (2019). Determining the optimal allocation of automated buses on a public transport network. In: : . Paper presented at Transportforum, Linköping, Sweden, 10-11 January 2019.
Open this publication in new window or tab >>Determining the optimal allocation of automated buses on a public transport network
2019 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Background: This research is driven by the general need for affordable, frequent and convenient Public Transport (PT) solutions. Over the last years the advances in the sector of autonomous systems have triggered studies on their effect on PT. AB lower the operational costs due to the removal of labor costs, which in developed countries account for more than half of the overall operational costs. These lower operational costs are expected to lead to higher service frequencies. The introduction of more diverse vehicle sizes is then possible and economical which will allow the operators to target the user demand better than with a fixed sized vehicle fleet. In this we analyse the use of AB systems in existing PT networks by:

- define an AV specific objective function

- integrate AV systems in a mesoscopic simulation framework

- extract KPIs for the economic deployment of AB systems 

This study aims at answering the following research questions:

- How can AB systems be used to improve passenger and operator costs on existing lines?

- What are the implications of the cost trade off in terms of the defined KPI?

- On which lines is the deployment of AB systems most interesting in terms of social welfare?

Methods: The implementation of the framework adopts a simulation based optimization approach. The multi-agent simulation software (BusMezzo) uses the networks routes and the decision variables as input values. Subsequently the simulation is executed, and the filtered results will be handed to the Genetic Algorithm optimization. The objective function minimizes the overall cost which is the sum of operator costs (capital costs & operation cost) and user cost (travel time, waiting time, ticket cost,..). This loop is executed until convergence. The decision variables for the optimization module are the vehicle capacity, the frequency per route and the vehicle type. For validation of the optimization approach described above a brute force analysis is done on the synthetic Network provided by Spiess & Florian. In the brute force analysis the entire solution space for the network is displayed and can be analyzed. This allows for deeper understanding of the underlying processes and validates the optimization results. With the knowledge of this approach the optimization parameters are configured.

Results: The proposed model was applied to a on-going pilot case study in the area of Kista in Stockholm. The proposed model is generally applicability for larger scale problems. Possible applications of the proposed methodology are:

- tool for identifying the most promising areas for introducing AB

- measurement for the economic impact of AB Systems on PT

- the design of the network for a mixed operation

Potential extensions of the model include the fleet composition and fleet size per line of special AB zones in high user demand areas.

The main results and conclusions are:

- Frequency and Capacity have comparable impact on total cost

- Introducing Autonomous Vehicle on high demand lines is beneficial

- There are "sweet spots" for operating for operating vehicle mixes

- some configurations are only profitably operable with autonomous vehicle

National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-334985 (URN)
Conference
Transportforum, Linköping, Sweden, 10-11 January 2019
Funder
Vinnova, 2016-02554Integrated Transport Research Lab (ITRL)
Note

QC 20230831

Available from: 2023-08-30 Created: 2023-08-30 Last updated: 2023-08-31Bibliographically approved
Hatzenbühler, J., Jenelius, E. & Cats, O. (2018). Determining the optimal allocation of automated buses. In: : . Paper presented at 7th Symposium of the European Association for Research in Transportation (hEART), Athens, Greece, 5-7 September 2018.
Open this publication in new window or tab >>Determining the optimal allocation of automated buses
2018 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-333826 (URN)
Conference
7th Symposium of the European Association for Research in Transportation (hEART), Athens, Greece, 5-7 September 2018
Funder
Vinnova, 2016-05313
Note

QC 20230814

Available from: 2023-08-11 Created: 2023-08-11 Last updated: 2023-08-14Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9447-2823

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