Transportation Research Record: Journal of the Transportation Research Board, 2010
To facilitate the development of dynamic activity-based models for transport demand, the FEATHERS... more To facilitate the development of dynamic activity-based models for transport demand, the FEATHERS framework was developed. This framework suggests a four-stage development trajectory for a smooth transition from the four-step models toward static activity-based models in the short term and dynamic activity-based models in the long term. The development stages discussed in this paper range from an initial static activity-based model without traffic assignment to a dynamic activity-based model that incorporates rescheduling, learning effects, and traffic routing. To illustrate the FEATHERS framework, work that has been done on the development of static and dynamic activity-based models for Flanders (Belgium) and the Netherlands is discussed. First, the data collection is presented. Next, the four-stage activity-based model development trajectory is discussed in detail. The paper concludes with the presentation of the modular FEATHERS framework, which discusses the functionalities of t...
XIX IMEKO World Congress Fundamental and Applied Metrology September 6−11, 2009, Lisbon, Portugal... more XIX IMEKO World Congress Fundamental and Applied Metrology September 6−11, 2009, Lisbon, Portugal ... IMPLEMENTATION, VALIDATION AND APPLICATION OF A METHOD OF EVALUATION OF URINARY 1-HYDROXYPYRENE AS AN INDICATOR OF HUMAN ...
Verzameling van activiteiten-en verplaatsingsgegevens met behulp van een met GPS uitgeruste zakco... more Verzameling van activiteiten-en verplaatsingsgegevens met behulp van een met GPS uitgeruste zakcomputer. In deze paper wordt de ontwikkeling van een software toepassing voor de verzameling van activiteiten-en verplaatsingsgegevens in de vorm van dagboekjes uiteengezet. De software wordt ontwikkeld voor gebruik op een met GPS uitgeruste zakcomputer. De opbouw van deze paper is als volgt: eerst wordt een verantwoording voor de keuze voor het verzamelen van activiteiten-en verplaatsingsgegevens onder de vorm van dagboekjes gegeven. Vervolgens worden de voor-en de nadelen van het gebruik van een met GPS uitgeruste zakcomputer toegelicht. De functionele beschrijving van de software toepassing wordt op basis van de functionele modules waaruit de toepassing bestaat uiteengezet. Vervolgens wordt elk van de reeds in een prototype van de software geïmplementeerde modules in detail beschreven. Tenslotte worden een aantal in de toekomst te implementeren modules vermeld.
In addition to their environmental impact, road traffic congestions have been recognized to serio... more In addition to their environmental impact, road traffic congestions have been recognized to seriously affect commuters’ safety as well as the performance of transportation systems. To address these issues, various Traffic Incident Management (TIM) systems have been implemented. Recent systems are particularly focusing on the integration of promising emergent technologies such as the Internet of Things. However, thorough studies are still necessary to make sure that these technologies are compatible with existing systems and effective within their context of use. The main goal of this research is to develop a smart TIM system which is based on Car2X communications and which aims at improving both traffic safety, commuters’ mobility, and gas emissions. To assess the effectiveness of our solution, we use the following measures: stops delay, stops all, vehicle delay, travel time, gas emissions, and fuel consumption. This paper also outlines how we use our simulation platform (which was developed based on VISSIM and Python) to quantify the benefits of using Car2X communications. We run our simulations on Muscat Expressway in the Sultanate of Oman. Results are promising and include (1) the travel time decreased by 6%; (2) the average stop delay and vehicle stops were reduced by at least 9% and 27% respectively; and (3) there is a total decrease in fuel consumption and carbon monoxide emissions by approximately 16%.
Developing an optimised activity type annotation method based on classification accuracy and entr... more Developing an optimised activity type annotation method based on classification accuracy and entropy indices The generation of substantial amounts of travel and mobility related data has spawned the emergence of the era of big data. However, this data generally lacks activity-travel information such as trip purpose. This deficiency led to the development of trip purpose inference (activity type imputation / annotation) techniques, of which the performance depends on the available input data and the (number of) activity type classes to infer. Aggregating activity types strongly increases the inference accuracy and is usually left to the discretion of the researcher. As this is open for interpretation, it undermines the reported inference accuracy. This study developed an optimised classification methodology by identifying classes of activity types with an optimal balance between improving model accuracy, and preserving activity information from the original data set. A sensitivity analysis was performed. Additionally, several machine learning algorithms are experimented with. The proposed method may be applied to any study area.
Abstract Increasing evidence suggests that neighborhood-based measures of socioeconomic status ar... more Abstract Increasing evidence suggests that neighborhood-based measures of socioeconomic status are correlated with traffic injury. The main objective of this study is to determine the differences in associations between predictive variables and injury crashes (i.e. including injury and fatal crashes). This study makes a novel contribution by establishing the association between traffic casualties and socio-demographic, socioeconomic characteristics, traffic exposure data and road network variables, at the neighborhood-level while categorized by different genders and transport mode; ‘car driver’, ‘car passenger’ and ‘active mode users’ (i.e. pedestrians and cyclists). In this study an activity-based transportation model called FEATHERS (Forecasting Evolutionary Activity-Travel of Households and their Environmental RepercussionS) is utilized to produce exposure measures. Exposure measures are in the form of production/attraction trips for several traffic analysis zones (TAZ) in Flanders, Belgium. Analyzing crashes at a neighborhood-level provides important information that enables us to compare traffic safety of different neighborhoods. This information is used to identify safety problems in specific zones and consequently, implementing safety interventions to improve the traffic safety condition. This can be carried out by associating casualty counts with a number of factors (i.e. developing crash prediction models) which have macro-level characteristics, such as socio-demographic and network level exposure. The results indicate that socioeconomic variables are differently associated with casualties of different travel modes and genders. For instance, income level of residence of a TAZ is a significant predictor of male car driver injury crashes while it does not significantly contribute to the prediction of female car driver injury crashes.
Many activity-based models start by scheduling inflexible or mandatory activities (if present), b... more Many activity-based models start by scheduling inflexible or mandatory activities (if present), before more flexible activities. Often work and educational activities are assumed as most stringent and recognized as the only mandatory activities. According to this definition, only 45% of all schedules contains a mandatory activity (OVG single-day travel survey in Flanders, Belgium). This means 55% of schedules does not have a traditional mandatory-flexible activity structure. This research proposes a completely data-driven approach to reveal the real basic structure of individuals' schedules, i.e. the skeleton schedule sequence. To this end, a sequential clustering algorithm was developed. Furthermore, an in-depth analysis of the parameter settings was performed. The proposed method reveals a set of skeleton activity schedules and confirms the importance of work and education.
Transportation Research Record Journal of the Transportation Research Board
Electric power demand for household generated traffic is estimated as a function of time and space... more Electric power demand for household generated traffic is estimated as a function of time and space for the region of Flanders. An activity-based model is used to predict traffic demand. Electric vehicle (EV) type and charger characteristics are determined on the basis of car ownership and by assuming that EV categories market shares will be similar to the current ones for internal combustion engine vehicles (ICEV) published in government statistics. Charging opportunities at home and work locations are derived from the predicted schedules and by estimating the possibility to charge at work. Simulations are run for several EV market penetration levels and for specific BEV/PHEV (battery-only/pluggable hybrid) ratios. A single car is used to drive all trips in a daily schedule. Most of the Flemish schedules can be driven entirely by a BEV even after reducing published range values to account for range anxiety and for the over-estimated ranges resulting from tests according to standards. T...
Assessing the safety impacts of Travel Demand Management (TDM) policies is essential to be carrie... more Assessing the safety impacts of Travel Demand Management (TDM) policies is essential to be carried out by means of a proactive approach. Since TDM policies are typically implemented at an aggregate level, Crash Prediction Models (CPMs) should also be developed at a similar level of aggregation. These models should match better with the resolution at which TDM evaluations are performed. Therefore Zonal Crash Prediction Models (ZCPM's) are considered to construct the association between observed crashes and a set of predictor variables in each zone. This is carried out by the Generalized Linear Modeling (GLM) procedure with the assumption of Negative Binomial (NB) error distribution. Different exposure, network and socio-demographic variables of 2200 Traffic Analysis Zones (TAZs) are considered as predictors of crashes in the study area, Flanders, Belgium. To this end, an activity-based transportation model framework is applied to produce exposure measurements. Crash data used in ...
Een activiteitengebaseerde doorrekening van de impact van een gewijzigd openbaarvervoersaanbod in... more Een activiteitengebaseerde doorrekening van de impact van een gewijzigd openbaarvervoersaanbod in Vlaanderen -IMOB. Naast het grondgebruik is ook het beschikbare netwerk bepalend voor de uiteindelijke vervoerswijzekeuze. Een in Vlaanderen uitgevoerde strategische studie naar de impact van een gewijzigd openbaarvervoersaanbod op de totale vervoerswijzekeuze geeft antwoord op het vraagstuk wat de opbrengst zou zijn als gevolg van de investering in het openbaar vervoer.
Research on activity-based travel demand forecasting and activity-travel simulator has invited an... more Research on activity-based travel demand forecasting and activity-travel simulator has invited an international attention for the last two decades. Ways to develop the activity-based simulator may be manifold. It is obvious that importing an existing simulator that has been proven internationally likely reduces the development cost and the risk of failure. By definition of the activity-based approach, however, the details of an activity-based simulator inevitably relies on particular social, economic and cultural characteristics of the society where the simulator is developed. When importing such a simulator from overseas, the researcher should be aware of the importance of tuning the system for the society to which the imported system is applied. There are many potential works on this, including for example the tuning of data structure that is likely different form that of the original system. We authors do not aware of any research report on this yet. The current paper aims to report the result of research to transform the input data for applying an existing overseas activity-travel simulator to Seoul Metropolitan Area. To this end, the paper first introduces FEATHERS that was developed in Belgium having Albatross at the core of the system. FEATHERS Seoul that is under development to apply original FEATHERS to Seoul is briefly described and the related problems of data structure mismatching are discussed. The paper then reports the effort to alleviate the problems and the results.
Travel demand management (TDM) consists of a variety of policy measures that affect the effective... more Travel demand management (TDM) consists of a variety of policy measures that affect the effectiveness of transportation systems by changing travel behavior. The primary objective of such TDM strategies is not to improve traffic safety, although their impact on traffic safety should not be neglected. The main purpose of this study is to simulate the traffic safety impact of conducting a teleworking scenario (i.e. 5% of the working population engages in teleworking) in the study area, Flanders, Belgium. Since TDM strategies are usually conducted at a geographically aggregated level, crash prediction models (CPMs) should also be developed at an aggregate level. Given that crash occurrences are often spatially heterogeneous and are affected by many spatial variables, the existence of spatial correlation in the data is also examined. The results indicate the necessity of accounting for the spatial correlation when developing crash prediction models. Therefore zonal crash prediction models (ZCPMs) within the Geographically Weighted Generalized Linear Modeling (GWGLM) framework are developed to incorporate the spatial variations in association between the number of crashes (NOCs) (including fatal, severe and slight injury crashes recorded between 2004 and 2007) and other explanatory variables. Different exposure, network and socio-demographic variables of 2200 traffic analysis zones (TAZs) are considered as predictors of crashes. An activity-based transportation model framework is adopted to produce detailed exposure metrics. This enables to conduct a more detailed and reliable assessment while TDM strategies are inherently modeled in the activity-based models. In this study, several ZCPMs with different severity levels and crash types are developed to predict the NOCs for both the null and the teleworking scenario. The models show a considerable traffic safety benefit of conducting the teleworking scenario due to its impact on the reduction of total Vehicle Kilometers Traveled (VKT) by 3.15%. Implementing the teleworking scenario is predicted to reduce the annual VKT by 1.426 billion and total NOCs to decline by 2.62%.
This document contains the first deliverable of WP4 (D4.1). It represents the results of the DATA... more This document contains the first deliverable of WP4 (D4.1). It represents the results of the DATASIM project in WP4 during Year 2.
ABSTRACT Travel behavior simulated to reflect local characteristics becomes an important issue as... more ABSTRACT Travel behavior simulated to reflect local characteristics becomes an important issue as local governments increasingly attempt TDM specific to their local context. One possible way to achieve this is a combined effort from activity-based simulation and GIS-based spatial analysis. Existing research however lacks either the prediction of travel behavior from local context in the simulation or the encapsulation of sub-local differences in such predictions. The paper using a GIS-based spatial analysis aims to examine whether an activity-based model system simulates activity-travel behavior that reflects geographical characteristics of the study area at the level of Traffic Analysis Zone (TAZ). To this end, data was collected from Household Travel Survey in Seoul Metropolitan Area (SMA). FEATHERS Seoul (FS) synthesized population and simulated activity-travel behavior in the context of SMA for the base year of 2010 and the target year of 2030, respectively. A GIS-based spatial analysis was then applied to the resultant simulated activity-travel behavior. The major findings are following. First, spatial distribution of homogeneous simulated activity-travel groups distinguished three geographical areas in SMA with clear local contexts. Secondly, the changes in activity-travel behavior between the two distant years were in accordance with expectation along the social changes. Finally, global regression and geographically weighted regression respectively showed that the -association between activity-travel behavior and geographical characteristics is well supported across the study area and that localized regression relationships between TAZ variables and travel behavior also exists. The latter implies that a finetuning of activity-travel simulation is required for local transportation policy development.
Data Science and Simulation in Transportation Research, 2014
Over the last decades, the trip-based approach, also known as the four-step model, has been playi... more Over the last decades, the trip-based approach, also known as the four-step model, has been playing an unrivaled role in transportation demand research in Korea. It has been used to predict changes in traffic volume resulting from new transportation policy measures, and also has allowed conducting benefit-cost analyses for new infrastructure provisions. It has been increasingly difficult for the trip-based model to anticipate individual responses to new transportation policy inputs and infrastructure provision as the society becomes personalized and diversified. Activity-Based Modeling (ABM) approaches, predicting travel demand derived from individual activity participations, were introduced to complement the trip-based approach in this regard. The chapter introduces the Seoul ABM project that aims to first apply FEATHERS as an ABM to the data collected in Seoul Metropolitan Area (SMA) and then develop a prototype of the ABM framework for Korea. More specifically, the chapter first ...
FEATHERS is an activity-based micro-simulation modeling framework used for transport demand forec... more FEATHERS is an activity-based micro-simulation modeling framework used for transport demand forecasting. Currently, this framework is implemented for the Flanders region of Belgium and the most detailed travel demand data can be obtained at the Subzone level, which consists of 2,386 virtual units with an average area of 5.8 km 2. In this study, we investigated the transferability of applying the FEATHERS framework from the Subzone zoning system to a more disaggregated zoning system, i.e., Building block (BB), which is the most detailed geographical level currently applicable in Belgium consisting of 10,521 units with an average area of 1.3 km 2. In this paper, we elaborated the data processing procedure in order to implement the FEATHERS framework under the BB zoning system. The observed as well as the predicted travel demand in Flanders based on the two zoning systems were compared. The results indicated the validity and also the necessity of this extension.
Transportation Research Record: Journal of the Transportation Research Board, 2012
Assessment of the safety impacts of travel demand management (TDM) policies must be conducted pro... more Assessment of the safety impacts of travel demand management (TDM) policies must be conducted proactively. Because TDM policies are typically implemented at an aggregate level, crash prediction models should also be developed at a similar level. The resolution of these models should better match that at which evaluations of TDM policies are performed. Therefore, in this study zonal crash prediction models were considered to establish an association between observed crashes and a set of predictor variables in each zone. This analysis was performed with the generalized linear modeling procedure and the assumption of a negative binomial error distribution. Different exposure, network, and sociodemographic variables for 2,200 traffic analysis zones were considered predictors of crashes in the study area of Flanders, Belgium. An activity-based transportation model framework was applied to produce exposure measurements for crash data that consisted of injury crashes recorded between 2004 ...
Transportation Demand Management (TDM) is often referred to as a management strategy adopted by t... more Transportation Demand Management (TDM) is often referred to as a management strategy adopted by transport planners with the overall and wider goal to increase transport system efficiency. One of the possible measures that can be adopted in TDM is the implementation of telecommuting. A significant number of studies have been conducted in the past to evaluate the effect of telecommuting on peak-period trips. However it is less studied in literature whether teleworking also effectively and significantly reduces total vehicle travel. Indeed, travel reductions may be partly offset by additional vehicle trips conducted during the telecommuting time period, which normally would have been made during normal commuting as part of a trip chain. For this reason, a conventional modeling approach (approach 1) that has been taken from literature was adopted in this paper to calculate total kilometers of travel saved in the case telecommuting (assuming different shares of telecommuters) would mater...
Transportation Research Record: Journal of the Transportation Research Board, 2010
To facilitate the development of dynamic activity-based models for transport demand, the FEATHERS... more To facilitate the development of dynamic activity-based models for transport demand, the FEATHERS framework was developed. This framework suggests a four-stage development trajectory for a smooth transition from the four-step models toward static activity-based models in the short term and dynamic activity-based models in the long term. The development stages discussed in this paper range from an initial static activity-based model without traffic assignment to a dynamic activity-based model that incorporates rescheduling, learning effects, and traffic routing. To illustrate the FEATHERS framework, work that has been done on the development of static and dynamic activity-based models for Flanders (Belgium) and the Netherlands is discussed. First, the data collection is presented. Next, the four-stage activity-based model development trajectory is discussed in detail. The paper concludes with the presentation of the modular FEATHERS framework, which discusses the functionalities of t...
XIX IMEKO World Congress Fundamental and Applied Metrology September 6−11, 2009, Lisbon, Portugal... more XIX IMEKO World Congress Fundamental and Applied Metrology September 6−11, 2009, Lisbon, Portugal ... IMPLEMENTATION, VALIDATION AND APPLICATION OF A METHOD OF EVALUATION OF URINARY 1-HYDROXYPYRENE AS AN INDICATOR OF HUMAN ...
Verzameling van activiteiten-en verplaatsingsgegevens met behulp van een met GPS uitgeruste zakco... more Verzameling van activiteiten-en verplaatsingsgegevens met behulp van een met GPS uitgeruste zakcomputer. In deze paper wordt de ontwikkeling van een software toepassing voor de verzameling van activiteiten-en verplaatsingsgegevens in de vorm van dagboekjes uiteengezet. De software wordt ontwikkeld voor gebruik op een met GPS uitgeruste zakcomputer. De opbouw van deze paper is als volgt: eerst wordt een verantwoording voor de keuze voor het verzamelen van activiteiten-en verplaatsingsgegevens onder de vorm van dagboekjes gegeven. Vervolgens worden de voor-en de nadelen van het gebruik van een met GPS uitgeruste zakcomputer toegelicht. De functionele beschrijving van de software toepassing wordt op basis van de functionele modules waaruit de toepassing bestaat uiteengezet. Vervolgens wordt elk van de reeds in een prototype van de software geïmplementeerde modules in detail beschreven. Tenslotte worden een aantal in de toekomst te implementeren modules vermeld.
In addition to their environmental impact, road traffic congestions have been recognized to serio... more In addition to their environmental impact, road traffic congestions have been recognized to seriously affect commuters’ safety as well as the performance of transportation systems. To address these issues, various Traffic Incident Management (TIM) systems have been implemented. Recent systems are particularly focusing on the integration of promising emergent technologies such as the Internet of Things. However, thorough studies are still necessary to make sure that these technologies are compatible with existing systems and effective within their context of use. The main goal of this research is to develop a smart TIM system which is based on Car2X communications and which aims at improving both traffic safety, commuters’ mobility, and gas emissions. To assess the effectiveness of our solution, we use the following measures: stops delay, stops all, vehicle delay, travel time, gas emissions, and fuel consumption. This paper also outlines how we use our simulation platform (which was developed based on VISSIM and Python) to quantify the benefits of using Car2X communications. We run our simulations on Muscat Expressway in the Sultanate of Oman. Results are promising and include (1) the travel time decreased by 6%; (2) the average stop delay and vehicle stops were reduced by at least 9% and 27% respectively; and (3) there is a total decrease in fuel consumption and carbon monoxide emissions by approximately 16%.
Developing an optimised activity type annotation method based on classification accuracy and entr... more Developing an optimised activity type annotation method based on classification accuracy and entropy indices The generation of substantial amounts of travel and mobility related data has spawned the emergence of the era of big data. However, this data generally lacks activity-travel information such as trip purpose. This deficiency led to the development of trip purpose inference (activity type imputation / annotation) techniques, of which the performance depends on the available input data and the (number of) activity type classes to infer. Aggregating activity types strongly increases the inference accuracy and is usually left to the discretion of the researcher. As this is open for interpretation, it undermines the reported inference accuracy. This study developed an optimised classification methodology by identifying classes of activity types with an optimal balance between improving model accuracy, and preserving activity information from the original data set. A sensitivity analysis was performed. Additionally, several machine learning algorithms are experimented with. The proposed method may be applied to any study area.
Abstract Increasing evidence suggests that neighborhood-based measures of socioeconomic status ar... more Abstract Increasing evidence suggests that neighborhood-based measures of socioeconomic status are correlated with traffic injury. The main objective of this study is to determine the differences in associations between predictive variables and injury crashes (i.e. including injury and fatal crashes). This study makes a novel contribution by establishing the association between traffic casualties and socio-demographic, socioeconomic characteristics, traffic exposure data and road network variables, at the neighborhood-level while categorized by different genders and transport mode; ‘car driver’, ‘car passenger’ and ‘active mode users’ (i.e. pedestrians and cyclists). In this study an activity-based transportation model called FEATHERS (Forecasting Evolutionary Activity-Travel of Households and their Environmental RepercussionS) is utilized to produce exposure measures. Exposure measures are in the form of production/attraction trips for several traffic analysis zones (TAZ) in Flanders, Belgium. Analyzing crashes at a neighborhood-level provides important information that enables us to compare traffic safety of different neighborhoods. This information is used to identify safety problems in specific zones and consequently, implementing safety interventions to improve the traffic safety condition. This can be carried out by associating casualty counts with a number of factors (i.e. developing crash prediction models) which have macro-level characteristics, such as socio-demographic and network level exposure. The results indicate that socioeconomic variables are differently associated with casualties of different travel modes and genders. For instance, income level of residence of a TAZ is a significant predictor of male car driver injury crashes while it does not significantly contribute to the prediction of female car driver injury crashes.
Many activity-based models start by scheduling inflexible or mandatory activities (if present), b... more Many activity-based models start by scheduling inflexible or mandatory activities (if present), before more flexible activities. Often work and educational activities are assumed as most stringent and recognized as the only mandatory activities. According to this definition, only 45% of all schedules contains a mandatory activity (OVG single-day travel survey in Flanders, Belgium). This means 55% of schedules does not have a traditional mandatory-flexible activity structure. This research proposes a completely data-driven approach to reveal the real basic structure of individuals' schedules, i.e. the skeleton schedule sequence. To this end, a sequential clustering algorithm was developed. Furthermore, an in-depth analysis of the parameter settings was performed. The proposed method reveals a set of skeleton activity schedules and confirms the importance of work and education.
Transportation Research Record Journal of the Transportation Research Board
Electric power demand for household generated traffic is estimated as a function of time and space... more Electric power demand for household generated traffic is estimated as a function of time and space for the region of Flanders. An activity-based model is used to predict traffic demand. Electric vehicle (EV) type and charger characteristics are determined on the basis of car ownership and by assuming that EV categories market shares will be similar to the current ones for internal combustion engine vehicles (ICEV) published in government statistics. Charging opportunities at home and work locations are derived from the predicted schedules and by estimating the possibility to charge at work. Simulations are run for several EV market penetration levels and for specific BEV/PHEV (battery-only/pluggable hybrid) ratios. A single car is used to drive all trips in a daily schedule. Most of the Flemish schedules can be driven entirely by a BEV even after reducing published range values to account for range anxiety and for the over-estimated ranges resulting from tests according to standards. T...
Assessing the safety impacts of Travel Demand Management (TDM) policies is essential to be carrie... more Assessing the safety impacts of Travel Demand Management (TDM) policies is essential to be carried out by means of a proactive approach. Since TDM policies are typically implemented at an aggregate level, Crash Prediction Models (CPMs) should also be developed at a similar level of aggregation. These models should match better with the resolution at which TDM evaluations are performed. Therefore Zonal Crash Prediction Models (ZCPM's) are considered to construct the association between observed crashes and a set of predictor variables in each zone. This is carried out by the Generalized Linear Modeling (GLM) procedure with the assumption of Negative Binomial (NB) error distribution. Different exposure, network and socio-demographic variables of 2200 Traffic Analysis Zones (TAZs) are considered as predictors of crashes in the study area, Flanders, Belgium. To this end, an activity-based transportation model framework is applied to produce exposure measurements. Crash data used in ...
Een activiteitengebaseerde doorrekening van de impact van een gewijzigd openbaarvervoersaanbod in... more Een activiteitengebaseerde doorrekening van de impact van een gewijzigd openbaarvervoersaanbod in Vlaanderen -IMOB. Naast het grondgebruik is ook het beschikbare netwerk bepalend voor de uiteindelijke vervoerswijzekeuze. Een in Vlaanderen uitgevoerde strategische studie naar de impact van een gewijzigd openbaarvervoersaanbod op de totale vervoerswijzekeuze geeft antwoord op het vraagstuk wat de opbrengst zou zijn als gevolg van de investering in het openbaar vervoer.
Research on activity-based travel demand forecasting and activity-travel simulator has invited an... more Research on activity-based travel demand forecasting and activity-travel simulator has invited an international attention for the last two decades. Ways to develop the activity-based simulator may be manifold. It is obvious that importing an existing simulator that has been proven internationally likely reduces the development cost and the risk of failure. By definition of the activity-based approach, however, the details of an activity-based simulator inevitably relies on particular social, economic and cultural characteristics of the society where the simulator is developed. When importing such a simulator from overseas, the researcher should be aware of the importance of tuning the system for the society to which the imported system is applied. There are many potential works on this, including for example the tuning of data structure that is likely different form that of the original system. We authors do not aware of any research report on this yet. The current paper aims to report the result of research to transform the input data for applying an existing overseas activity-travel simulator to Seoul Metropolitan Area. To this end, the paper first introduces FEATHERS that was developed in Belgium having Albatross at the core of the system. FEATHERS Seoul that is under development to apply original FEATHERS to Seoul is briefly described and the related problems of data structure mismatching are discussed. The paper then reports the effort to alleviate the problems and the results.
Travel demand management (TDM) consists of a variety of policy measures that affect the effective... more Travel demand management (TDM) consists of a variety of policy measures that affect the effectiveness of transportation systems by changing travel behavior. The primary objective of such TDM strategies is not to improve traffic safety, although their impact on traffic safety should not be neglected. The main purpose of this study is to simulate the traffic safety impact of conducting a teleworking scenario (i.e. 5% of the working population engages in teleworking) in the study area, Flanders, Belgium. Since TDM strategies are usually conducted at a geographically aggregated level, crash prediction models (CPMs) should also be developed at an aggregate level. Given that crash occurrences are often spatially heterogeneous and are affected by many spatial variables, the existence of spatial correlation in the data is also examined. The results indicate the necessity of accounting for the spatial correlation when developing crash prediction models. Therefore zonal crash prediction models (ZCPMs) within the Geographically Weighted Generalized Linear Modeling (GWGLM) framework are developed to incorporate the spatial variations in association between the number of crashes (NOCs) (including fatal, severe and slight injury crashes recorded between 2004 and 2007) and other explanatory variables. Different exposure, network and socio-demographic variables of 2200 traffic analysis zones (TAZs) are considered as predictors of crashes. An activity-based transportation model framework is adopted to produce detailed exposure metrics. This enables to conduct a more detailed and reliable assessment while TDM strategies are inherently modeled in the activity-based models. In this study, several ZCPMs with different severity levels and crash types are developed to predict the NOCs for both the null and the teleworking scenario. The models show a considerable traffic safety benefit of conducting the teleworking scenario due to its impact on the reduction of total Vehicle Kilometers Traveled (VKT) by 3.15%. Implementing the teleworking scenario is predicted to reduce the annual VKT by 1.426 billion and total NOCs to decline by 2.62%.
This document contains the first deliverable of WP4 (D4.1). It represents the results of the DATA... more This document contains the first deliverable of WP4 (D4.1). It represents the results of the DATASIM project in WP4 during Year 2.
ABSTRACT Travel behavior simulated to reflect local characteristics becomes an important issue as... more ABSTRACT Travel behavior simulated to reflect local characteristics becomes an important issue as local governments increasingly attempt TDM specific to their local context. One possible way to achieve this is a combined effort from activity-based simulation and GIS-based spatial analysis. Existing research however lacks either the prediction of travel behavior from local context in the simulation or the encapsulation of sub-local differences in such predictions. The paper using a GIS-based spatial analysis aims to examine whether an activity-based model system simulates activity-travel behavior that reflects geographical characteristics of the study area at the level of Traffic Analysis Zone (TAZ). To this end, data was collected from Household Travel Survey in Seoul Metropolitan Area (SMA). FEATHERS Seoul (FS) synthesized population and simulated activity-travel behavior in the context of SMA for the base year of 2010 and the target year of 2030, respectively. A GIS-based spatial analysis was then applied to the resultant simulated activity-travel behavior. The major findings are following. First, spatial distribution of homogeneous simulated activity-travel groups distinguished three geographical areas in SMA with clear local contexts. Secondly, the changes in activity-travel behavior between the two distant years were in accordance with expectation along the social changes. Finally, global regression and geographically weighted regression respectively showed that the -association between activity-travel behavior and geographical characteristics is well supported across the study area and that localized regression relationships between TAZ variables and travel behavior also exists. The latter implies that a finetuning of activity-travel simulation is required for local transportation policy development.
Data Science and Simulation in Transportation Research, 2014
Over the last decades, the trip-based approach, also known as the four-step model, has been playi... more Over the last decades, the trip-based approach, also known as the four-step model, has been playing an unrivaled role in transportation demand research in Korea. It has been used to predict changes in traffic volume resulting from new transportation policy measures, and also has allowed conducting benefit-cost analyses for new infrastructure provisions. It has been increasingly difficult for the trip-based model to anticipate individual responses to new transportation policy inputs and infrastructure provision as the society becomes personalized and diversified. Activity-Based Modeling (ABM) approaches, predicting travel demand derived from individual activity participations, were introduced to complement the trip-based approach in this regard. The chapter introduces the Seoul ABM project that aims to first apply FEATHERS as an ABM to the data collected in Seoul Metropolitan Area (SMA) and then develop a prototype of the ABM framework for Korea. More specifically, the chapter first ...
FEATHERS is an activity-based micro-simulation modeling framework used for transport demand forec... more FEATHERS is an activity-based micro-simulation modeling framework used for transport demand forecasting. Currently, this framework is implemented for the Flanders region of Belgium and the most detailed travel demand data can be obtained at the Subzone level, which consists of 2,386 virtual units with an average area of 5.8 km 2. In this study, we investigated the transferability of applying the FEATHERS framework from the Subzone zoning system to a more disaggregated zoning system, i.e., Building block (BB), which is the most detailed geographical level currently applicable in Belgium consisting of 10,521 units with an average area of 1.3 km 2. In this paper, we elaborated the data processing procedure in order to implement the FEATHERS framework under the BB zoning system. The observed as well as the predicted travel demand in Flanders based on the two zoning systems were compared. The results indicated the validity and also the necessity of this extension.
Transportation Research Record: Journal of the Transportation Research Board, 2012
Assessment of the safety impacts of travel demand management (TDM) policies must be conducted pro... more Assessment of the safety impacts of travel demand management (TDM) policies must be conducted proactively. Because TDM policies are typically implemented at an aggregate level, crash prediction models should also be developed at a similar level. The resolution of these models should better match that at which evaluations of TDM policies are performed. Therefore, in this study zonal crash prediction models were considered to establish an association between observed crashes and a set of predictor variables in each zone. This analysis was performed with the generalized linear modeling procedure and the assumption of a negative binomial error distribution. Different exposure, network, and sociodemographic variables for 2,200 traffic analysis zones were considered predictors of crashes in the study area of Flanders, Belgium. An activity-based transportation model framework was applied to produce exposure measurements for crash data that consisted of injury crashes recorded between 2004 ...
Transportation Demand Management (TDM) is often referred to as a management strategy adopted by t... more Transportation Demand Management (TDM) is often referred to as a management strategy adopted by transport planners with the overall and wider goal to increase transport system efficiency. One of the possible measures that can be adopted in TDM is the implementation of telecommuting. A significant number of studies have been conducted in the past to evaluate the effect of telecommuting on peak-period trips. However it is less studied in literature whether teleworking also effectively and significantly reduces total vehicle travel. Indeed, travel reductions may be partly offset by additional vehicle trips conducted during the telecommuting time period, which normally would have been made during normal commuting as part of a trip chain. For this reason, a conventional modeling approach (approach 1) that has been taken from literature was adopted in this paper to calculate total kilometers of travel saved in the case telecommuting (assuming different shares of telecommuters) would mater...
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Papers by Bruno Kochan