Posts tagged modelling
Assessing and improving operational strategies for the benefit of passengers in rail-bound urban transport systems
Unplanned disruptions in transit can have consequent impacts on passengers. The more inconvenienced passengers are, the more likely operators will be negatively impacted. Yet so far, operators and researchers have addressed the rescheduling problem during disruptions mainly with a supply-side focus – timetable, crews and vehicles – and not with a passenger perspective. Urban rail transit particularly lacks insights in terms of passenger- focused rescheduling. Being able to assess the inconvenience experienced by passengers during disruptions compared with what they normally experience, and being able to compare how different rescheduling strategies affect them are therefore two major challenges.
The framework developed in this study precisely aims at tackling 8 these challenges. A case study of the metro of Rotterdam is used to test the framework developed in this paper. Alternative strategies are developed focusing on the incident phase (from the beginning of the incident until its cause is resolved). The application of the framework reveals that a regularity-focused rescheduling strategy would be beneficial for high-frequency service users. Realistically, yearly savings could amount to around €900,000 in terms of societal passenger costs for the operator in the Rotterdam area alone. However, the omnipresence of the punctuality paradigm, through which most operators plan and analyze operations, makes the implementation of passenger-focused strategies a challenging task for traffic controllers. The results of the study are valuable for transit operators worldwide and the framework can provide insights to decision-makers on the performance of different strategies, bringing to light trade-offs between supply and passenger sides during disruptions.
Read more of this research by Anne Durand: Paper TRB and Poster TRB
Performance assessment of fixed and flexible public transport in a multi agent simulation framework
The emergence of innovative mobility solutions that offer flexible transport services, is changing the way urban public transport systems will be designed. Such mobility solutions offer on demand transport services and hence can solve the problems inherent with traditional line based and schedule based public transport systems. It is essential to understand the dynamics of this new demand-supply market with co-existing and competing fixed and flexible public transport. However, the performance of the system comprising of users and transit services and the factors influencing them, have received limited attention in literature. In this paper a model is developed to analyse the system performance when the modes of fixed public transport and flexible public transport operate in competition. The model is implemented in the multi-agent simulation framework MATSim with dynamic assignment in which the users optimize their travel plan through iterative learning from the service experienced and altering their travel plan. The scenarios in which the flexible public transport offer private and shared services are considered. The system performance is analysed for varying fleet size of flexible public transport and ratio of cost of flexible to fixed public transport.
Find the paper HERE
Modelling Multimodal Transit Networks: Integration of bus networks with walking and cycling
Demand for (public) transportation is subject to dynamics affected by technological, spatial, societal and demographic aspects. The political environment, together with financial and spatial constraints limit the possibilities to address transit issues arising from growing demand through the construction of new infrastructure. Upgrading of existing services and improving integration over the entire trip chain (including cycling) are two options that can address these transport issues. However, transport planners and transport service operators often fail to include the entire trip when improving services, as improvement is normally achieved through the adaptations of characteristics (e.g. speeds, stop distances) of the services.
Our developed framework consists of two parts: one to assess the characteristics of the different bus services and their access and egress modes, and one to assess the effects of integration of these services, which includes the modelling and analysis in a regional transit model. The framework has successfully been applied to a case study showing that bus systems with higher frequencies and speeds can attract twice the amount of cyclists on the access and egress sides. It also shows that passengers accept longer access and egress distances with more positive characteristics of the bus service (higher speeds, higher frequencies).
Find the presentation of Judith Brand at MT-ITS in Napoli HERE
Find our paper HERE
Optimization of a passenger railway transportation plan considering mobility flows and service quality
This research focuses on designing transportation plan for SNCF Transilien (French railway
operator for the Parisian suburban mass transit). The objective is to develop methods
and decision support tools to propose a timetable adapted to the passenger demand in the
Parisian mass transit system, including comfort and reliability criterias.
This paper aims to present the first step of this research. We propose a graph theoretic
ILP formulation for the Line Planning Problem, minimizing both travelers travel time and
operating cost. We furthermore develop a multi-objective method to solve this problem.
This method offers a pool of solutions in order to let the final designer choose the solution.
We report computational results on real world instances provided from SNCF Transilien.
Check the RAIL Lille paper of Lucile Brethome et al. HERE
Inzichten in dynamische effecten van openbaar vervoer door combinatie van statische en dynamische OV modellen
Steden worden steeds populairder om te wonen, werken en te recreëren. Deze trek naar de stad legt steeds meer druk op de hoogwaardige OV-assen in en van/naar de stad. Naast snelheid en frequentie zijn betrouwbaarheid en drukte belangrijke kwaliteitsaspecten voor zowel reiziger als vervoerder. Om deze OV-assen hoogwaardig en efficiënt te kunnen (blijven) exploiteren zijn inzichten in te verwachte effecten van nieuwe ontwikkelingen en maatregelen essentieel. Afgelopen decennium zijn er grote stappen gezet op het gebied van OV modellering. Er zijn goede, statische modellen beschikbaar voor OV prognoses. Desondanks is voor beter inzicht in bijvoorbeeld toekomstige betrouwbaarheid en drukte behoefte aan een meer dynamische modelomgeving, zonder het hoge detailniveau van microsimulatie. TU Delft en Goudappel zijn daarom een verkenning gestart naar toepassing van dynamische OV toedelingsmodellen, (agent-based, mesoscopisch). De basis hiervoor, BusMezzo, is ontwikkeld door KTH Stockholm en wordt daarnaast ook al via TU Delft toegepast in Nederlandse studies.
Deze verkenning richt zich op het modelleren van openbaar vervoer met zowel OmniTRANS, de modelleringsoftware voor het gros van de regionale en stedelijke modellen in Nederland, als BusMezzo, een dynamisch simulatiemodel voor OV toedeling. Het doel van dit project is om te verkennen in hoeverre een dynamisch model waarde kan toevoegen ten opzichte van een statisch model, en welke stappen genomen moeten worden om deze modellen met elkaar te laten communiceren. Naast theoretische analyse is een case studie van de metro van Amsterdam uitgevoerd.
BusMezzo is in staat om elk voertuig en elke reiziger individueel te simuleren en kan daarmee de volledige interactie tussen reiziger en voertuig meenemen in de toedeling. De impact van crowding wordt volledig gemodelleerd, door het toepassen van volume-afhankelijke halteertijden, denied boarding, en door reizigers ervaren reistijd als gevolg van discomfort in drukke voertuigen. Hiermee ontstaat een verrijking ten opzichte van statische modellen.
Een wederzijdse uitwisseling van input en output data tussen de beide modellen is mogelijk. Het ligt voor de hand om een tweetrapsraket te maken van beide modellen, waarbij de kracht van beiden wordt gecombineerd. Hiermee kunnen meer en betere inzichten worden verkregen voor verwachte effecten van ontwikkelingen en/of OV maatregelen. Daarmee wordt een grote verbeterslag in prognoses en bijv. kostenbaten-analyses gemaakt.
Bekijk de Platos presentatie HIER
Improving predictions of the impact of disturbances on public transport usage based on smart card data
The availability of smart card data from public transport travelling the last decades allows analyzing current and predicting future public transport usage. Public transport models are commonly applied to predict ridership due to structural network changes, using a calibrated parameter set. Predicting the impact of planned disturbances, like temporary track closures, on public transport ridership is however an unexplored area. In the Netherlands, this area becomes increasingly important, given the many track closures operators are confronted with the last and upcoming years. We investigated the passenger impact of four planned disturbances on the public transport network of Den Haag, the Netherlands, by comparing predicted and realized public transport ridership using smart card data. A two-step search procedure is applied to find a parameter set resulting in higher prediction accuracy. We found that in-vehicle time in rail-replacing bus services is perceived ≈1.1 times more negatively compared to in-vehicle time perception in the initial tram line. Besides, passengers do not seem to perceive the theoretical benefit of the usually higher frequency of rail-replacement bus services compared to the frequency of the replaced tram line. At last, no higher waiting time perception for temporary rail-replacement services could be found, compared to regular tram and bus services. The new parameter set leads to substantially higher prediction accuracy compared to the default parameter set. It supports public transport operators to better predict the required supply of rail-replacement services and to predict the impact on their revenues.
Read our TRB paper HERE
Find the poster HERE
Data driven enhancement of public transport planning and operations: service reliability improvements and ridership predictions
Automatic Vehicle Location (AVL) and smartcard data are of great value in planning, design and operations of public transport. We developed a transport demand model, which utilizes smartcard data for overall and what-if analyses, by converting these data into passengers per line and OD-matrixes and allowing network changes on top of a base scenario. This new generation model serves in addition to the existing range of transport demand models and approaches. It proved itself in practice during a case study in The Hague, where it helped the operator gain valuable insights into the effect of small network changes, such as a higher frequency.
Data also supports measures to improve service reliability. We introduced a new network design dilemma, namely the length of a transit line vs. its reliability. Long lines offer many direct connections, thereby saving transfers. However, the variability in operation is often negatively related to the length of a line, leading to poorer schedule adherence and additional waiting time for passengers. A data driven case study shows that in the case of long lines with large variability, enhanced reliability resulting from splitting the line could result in less additional travel time. This advantage compensates for the additional time of transferring if the transfer point is well chosen.
Read the full paper here: TRA Conference 2016 Van Oort Data driven enhancement of PT
or check the poster: TRA2016 Conference Poster
New generation of public transport models: predicting ridership by smartcard data
In the public transport industry we observe the rise of a new generation of transport demand models. We applied Dutch smart card data for analysis of passenger volumes and routing and performed what-if analyses by using existing transport planning software. We focused specifically on public transport operators by providing them relative simple (easy to build, low calculation time) models to perform these what-if analyses. The data, including transfer information, is converted to passengers per line and an OD-matrix between stops. This matrix is assigned to the network to reproduce the measured passenger flows. After this step, what-if analysis becomes possible. The effects of line changes on route choice can already be investigated when fixed demand is assumed. However, by introducing an elastic demand model the realism of the modeled effects is improved, because network changes induce changes in level of service, which affects the demand for public transportation. This elastic demand model was applied on a case study in The Hague. We imported the smart card data into a transport model and connected the data with the network. The tool turned out to be very valuable for the operator to gain insights into the effects of small network changes.
In addition to this basic model, we also applied a capacity constrained assignment method. The most important aspects on which passengers base their choice for public transport travelling are the perceived travel time, costs, reliability and comfort. Despite this importance, comfort is often not explicitly considered when predicting demand. The case study results indicate that not considering capacity and comfort effects can lead to a substantial underestimation of effects of certain measures aiming to improve public transport. This means that benefits of measures that reduce crowding for both passengers and operators can now be quantified and incorporated in the decision-making process. We also illustrate that this extended modelling framework can be applied in practice, requiring short calculation times and leading to better predictions of public transport demand.
Find our ETC 2015 presentation HERE
Improving public transport decision making, planning and operations by using Big Data: Cases from Sweden and the Netherlands
New big data (sources) in the public transport industry enable to deal with major challenges such as elevating efficiency, increasing passenger ridership and satisfaction and facilitate the information flow between service providers and service users. This paper presents two actual cases from the Netherlands and Sweden in which automated data sources were utilized to support the planning and operational processes. The cases illustrate the benefits of using smartcard and vehicle positioning data. Due to the data (processing), valuable insights were gained helping to make the right choices and improve the public transport system.
Read our paper: Workshop paper IEEE ITSC 2015 and check our presentation: Presentation IEEE ITSC15
Robustness of multi-level public transport networks: A methodology to quantify robustness from a passenger perspective
Despite the importance of robust public transport networks, this topic has not been considered from a full passenger perspective yet in scientific literature and practice. To our best knowledge, this study is the first in which both exposure to large, non-recurrent disturbances and impact of these disturbances are analysed in a systematic and realistic way. Contrary to single-level network perspectives, we considered the integrated, total multi-level public transport network which remains available when a disturbance occurs. We developed a new methodology to identify the most vulnerable links in the multi-level public transport network and to quantify the societal costs of non-robustness of these vulnerable links. Besides, applying our methodology enables quantification of the robustness benefits of robustness measures, next to the costs of such measures. Therefore, our methodology can support and rationalize the decision-making process of public transport operators and authorities regarding the implementation of different robustness measures.
Read the full paper: INSTR2015-Yap et al.
Find our presentation: INSTR2015 Presentation Yap et al.