TransportmetricaPub Date : 2011-05-01DOI: 10.1080/18128600903322333
K. Martens, E. Hurvitz
{"title":"Distributive impacts of demand-based modelling","authors":"K. Martens, E. Hurvitz","doi":"10.1080/18128600903322333","DOIUrl":"https://doi.org/10.1080/18128600903322333","url":null,"abstract":"Transport demand models play a crucial role in the distribution of transport facilities, and hence accessibility, over population groups. The goal of this article is to assess the distributive impacts of the widely-used four-step, demand-based, transport model. This article starts from the hypothesis that the consecutive application of the four-step model over a number of years, and successive investments in transport infrastructure consistent with the model results, will widen existing gaps between high-mobile and low-mobile groups, in terms of transport facilities and accessibility available to each group. A simplified four-step model is then developed to test the hypothesis under different policy scenarios. The results are mixed. In each scenario, gaps between high-mobile and low-mobile groups are increasing and decreasing at the same time. Against expectations, the distributive implications of demand-based modelling seem to depend on the situation and the focus of analysis. Given the unpredictable distributive impacts, it is suggested that explicit justice indicators be incorporated in transport modelling if it is to contribute to a more just distribution of transport facilities and accessibility over population groups.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"181 - 200"},"PeriodicalIF":0.0,"publicationDate":"2011-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/18128600903322333","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59925202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TransportmetricaPub Date : 2011-05-01DOI: 10.1080/18128600903500110
J. Einbeck, J. Dwyer
{"title":"Using principal curves to analyse traffic patterns on freeways","authors":"J. Einbeck, J. Dwyer","doi":"10.1080/18128600903500110","DOIUrl":"https://doi.org/10.1080/18128600903500110","url":null,"abstract":"Scatterplots of traffic speed versus flow have received considerable attention over the past decades due to their characteristic half-moon shape. Modelling data of this type is difficult as both variables are actually not a function of each other in the sense of causality, but are rather jointly generated by a third latent variable, which is a monotone function of the traffic density. We propose local principal curves (LPCs) as a tool to describe and model speed–flow data, which takes this viewpoint into account. We introduce the concept of calibration curves to determine the relationship between the latent variable (represented by the parametrisation of the principal curve) and the traffic density. We apply LPCs to a variety of speed–flow diagrams from Californian freeways, including some so far unreported patterns.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"229 - 246"},"PeriodicalIF":0.0,"publicationDate":"2011-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/18128600903500110","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59925448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TransportmetricaPub Date : 2011-03-22DOI: 10.1080/18128602.2010.520276
Tomás Ruiz, M. Roorda
{"title":"Assessing planning decisions by activity type during the scheduling process","authors":"Tomás Ruiz, M. Roorda","doi":"10.1080/18128602.2010.520276","DOIUrl":"https://doi.org/10.1080/18128602.2010.520276","url":null,"abstract":"Existing activity-based models still make assumptions about scheduling decision processes that are not well-informed by empirical evidence. In this article, a step forward is taken to better understand the activity-scheduling process and to improve activity-based models. In particular, different planning decision mechanisms depending on several activity type classifications are explored. First, models describing the planning of several aggregate activity types are considered. For these activities, three planning decisions are studied: location, planning time horizon and rescheduling. The ‘with whom’ planning decision is also studied when subtypes of recreational/entertainment activities are investigated in depth. Significant differences are found in modelling results for each activity type and subtype and each planning decision. These results confirm the existence of different mechanisms underlying the activity-travel decision process when activity types and subtypes are considered. Important conclusions related to the improvement of microsimulation models are highlighted.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"417 - 442"},"PeriodicalIF":0.0,"publicationDate":"2011-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/18128602.2010.520276","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59925677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TransportmetricaPub Date : 2011-03-21DOI: 10.1080/18128602.2010.505590
Fedja Netjasov, M. Janić, V. Tosic
{"title":"Developing a generic metric of terminal airspace traffic complexity","authors":"Fedja Netjasov, M. Janić, V. Tosic","doi":"10.1080/18128602.2010.505590","DOIUrl":"https://doi.org/10.1080/18128602.2010.505590","url":null,"abstract":"This article develops a generic metric for measuring the complexity of a given terminal airspace (TMA). The metric includes static and dynamic complexity, both consisting of the complexity component for arriving and departing traffic. The main objective of the developed metric is as follows: evaluation of particular alternative solutions for airspace organisation and design and related air traffic complexity under the given circumstances, which could be used for planning purposes at the strategic and the tactical level. For this reason, the proposed metric reflects the expected complexity over a certain time period, rather than the current value of complexity. The main factors influencing complexity of a given TMA are: configuration of TMA, which implies among other factors, the number and length of arrival/departure trajectories, the airport(s) runway system capacity, air traffic volume, aircraft fleet mix, spatial distribution of traffic and the air traffic control separation rules. Unlike most other approaches, the one presented in this article disregards the air traffic controller workload issue from explicit consideration, but indicates the level of complexity which could influence the workload that he or she could be faced with under the specified circumstances. The output consists of complexity values dependent of the configuration, i.e. three-dimensional geometry of the given TMA and approach/departure trajectories in it, air traffic volume, aircraft fleet mix and the spatial distribution of traffic. The developed complexity metric has been applied to TMA traffic around London Heathrow Airport, UK.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"369 - 394"},"PeriodicalIF":0.0,"publicationDate":"2011-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/18128602.2010.505590","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59925411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TransportmetricaPub Date : 2011-03-21DOI: 10.1080/18128602.2010.520138
Donggen Wang, Jiukun Li
{"title":"A two-level multiple discrete-continuous model of time allocation to virtual and physical activities","authors":"Donggen Wang, Jiukun Li","doi":"10.1080/18128602.2010.520138","DOIUrl":"https://doi.org/10.1080/18128602.2010.520138","url":null,"abstract":"This article develops a model to study individuals’ activity choice and time allocation in the physical and virtual spaces. Based on the recent advancement in modeling multiple discrete-continuous choices, this article develops a so-called two-level nested multiple discrete-continuous model. The model and its estimation algorithm are tested by a case study in Hong Kong in which the activity diaries of 330 respondents in the physical and virtual spaces within 24 h were collected. The model can be used to investigate the bi-directional interactions between activities and time use in physical and virtual spaces and their implications for physical travel. It may also be applied to analyse the impacts of social, economical and spatial factors on participation in and time allocation to virtual and physical activities. The model may also be applied to study transportation, marketing and tourism problems involving two-level multiple discrete-continuous choices.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"395 - 416"},"PeriodicalIF":0.0,"publicationDate":"2011-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/18128602.2010.520138","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59925632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TransportmetricaPub Date : 2011-03-01DOI: 10.1080/18128600903312789
B. Jia, Xingang Li, Tao Chen, R. Jiang, Ziyou Gao
{"title":"Cellular automaton model with time gap dependent randomisation under Kerner's three-phase traffic theory","authors":"B. Jia, Xingang Li, Tao Chen, R. Jiang, Ziyou Gao","doi":"10.1080/18128600903312789","DOIUrl":"https://doi.org/10.1080/18128600903312789","url":null,"abstract":"In this article, a new cellular automaton traffic flow model, in which randomisation effect is enhanced with the decrease of time gap and the long time stopped vehicle has large randomisation probability, is presented. Both periodic and open boundary conditions are considered. Under periodic boundary condition, the fundamental diagram and the properties of synchronised flow are studied in detail. Under open boundary condition, different congested patterns induced by an on-ramp are analysed. The results are consistent with the well-known results of Kerner's three-phase traffic theory published before.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"127 - 140"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/18128600903312789","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59925573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TransportmetricaPub Date : 2011-03-01DOI: 10.1080/18128600903313936
Wen-jun Sun, S. Wong, Peng Zhang, Chi-Wang Shu
{"title":"A shock-fitting algorithm for the Lighthill–Whitham–Richards model on inhomogeneous highways","authors":"Wen-jun Sun, S. Wong, Peng Zhang, Chi-Wang Shu","doi":"10.1080/18128600903313936","DOIUrl":"https://doi.org/10.1080/18128600903313936","url":null,"abstract":"The analytical shock-fitting algorithm outperforms traditional numerical methods in solving the Lighthill–Whitham–Richards (LWR) traffic flow model for homogeneous highways. In this study, we extend the algorithm to an inhomogeneous highway in which two homogeneous sections with different fundamental diagrams are connected by a junction (interface). According to the entropy condition of the Riemann problem, the flow conditions at the interface can be categorized into four groups, and the density on both sides of the interface can be uniquely determined. Based on the physical conditions, we construct a fictitious element as an appropriate boundary condition for each homogeneous section. Consequently, the Riemann problem of an inhomogeneous highway can be transformed into a problem of equivalent homogeneous sections to which the shock-fitting algorithm can be applied. We apply this algorithm to some representative traffic flow cases and compare the results with numerical solutions obtained using the Weighted Essentially Non-Oscillatory (WENO) scheme.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"163 - 180"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/18128600903313936","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59925151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TransportmetricaPub Date : 2011-03-01DOI: 10.1080/18128600903351001
Padmakumar Radhakrishnan, Tom V. Mathew
{"title":"Passenger car units and saturation flow models for highly heterogeneous traffic at urban signalised intersections","authors":"Padmakumar Radhakrishnan, Tom V. Mathew","doi":"10.1080/18128600903351001","DOIUrl":"https://doi.org/10.1080/18128600903351001","url":null,"abstract":"Signalisation is a traffic control strategy to ease the competition by providing right-of-way in a cyclic manner to conflicting traffic at intersections. Saturation flow is a major component in the design of signals, and is influenced by a variety of factors like vehicle composition, intersection geometry and driver's behaviour. The highway capacity manual (HCM) has recommended a saturation flow model primarily for homogeneous conditions, with limited ability to address heterogeneity. But the traffic in many parts of the world is highly heterogeneous and hence, defining a unified saturation flow concept is a challenging task. The variability in vehicle types necessitates the use of passenger car units (PCUs). This article proposes a methodology to develop a saturation flow model based on dynamic PCUs by a microscopic analysis. Field data from intersections of three Indian cities – Jaipur, Bangalore and Trivandrum – is used for the study. PCU values are derived from the field data, by minimising the difference between the observed and the ideal flow profiles. A new saturation flow model is then developed using the regression method. The model is validated with the saturation flows collected from different locations. In addition, the flow predicted by the saturation flow model is used to estimate delay using the HCM and Webster's models, and these delays are compared to the observed delays. The proposed model resulted in lower error compared to the conventional flow estimation techniques.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"141 - 162"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/18128600903351001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59925246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TransportmetricaPub Date : 2011-03-01DOI: 10.1080/18128600903251334
D. Ngoduy
{"title":"Multiclass first-order traffic model using stochastic fundamental diagrams","authors":"D. Ngoduy","doi":"10.1080/18128600903251334","DOIUrl":"https://doi.org/10.1080/18128600903251334","url":null,"abstract":"The first-order continuum traffic model has been extensively studied in the state-of-the-art of traffic flow theory due to its simplicity and capability to represent many real traffic problems, such as a shock-wave formation. Furthermore, recent extension of the first-order model to multiclass traffic dynamics has revealed some interesting non-linear traffic phenomena such as hysteresis and capacity drop. However, most of the existing first-order continuum models do not display the widely scattered flow–density relationship. We argue in this article that the widely scattered flow–density relationship might be caused by the random variations in driving behaviour. It is shown that both of the hysteresis transitions and the wide scattering can be reproduced by a multiclass first-order model with a stochastic setting in the model parameters. The simulation results support our findings and are in good agreement with the real data.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"111 - 125"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/18128600903251334","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59925554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TransportmetricaPub Date : 2011-02-12DOI: 10.1080/18128602.2010.498004
Seungjae Lee, Sungwhee Shin
{"title":"Variable message sign operating strategies: simple examples","authors":"Seungjae Lee, Sungwhee Shin","doi":"10.1080/18128602.2010.498004","DOIUrl":"https://doi.org/10.1080/18128602.2010.498004","url":null,"abstract":"This article presents a game-theoretic model of information transmission for variable message sign (VMS) operations. The model contains one VMS operator and many drivers. The operator wants to minimise the total travel time of all the drivers, while each driver wants to minimise his own travel time. The operator, who knows the actual traffic situation, sends drivers’ the traffic information strategically. The drivers evaluate the information from the operator, and then choose their optimal route. We model this situation as a cheap-talk game, which is one of the simplest forms of a Bayesian game. Depending on the shapes of the travel time function, the optimal information provision in equilibrium varies from full provision to partial provision.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"443 - 454"},"PeriodicalIF":0.0,"publicationDate":"2011-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/18128602.2010.498004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59925306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}