Transportation Research Record: Journal of the Transportation Research Board, 2008
Activity-based approaches to travel demand modeling are increasingly moving from theoretical to o... more Activity-based approaches to travel demand modeling are increasingly moving from theoretical to operational models. In this context, agent-based micro-simulation models are a promising approach since they explicitly conceive travel as an emergent phenomenon from peoples' activity characteristics, and more explicitly, from their activity scheduling processes. Behaviorally, activity-scheduling processes are influenced not only by individuals' characteristics, but also by the other people with whom they interact. Thus, the activity scheduling process has an intrinsic social context. Using social activities as a case study, the objective of this paper is to empirically investigate the relationship between the social context (measured by with whom the respondents interacted) and two key aspects of activity scheduling: start time and duration. Econometric models of the combined decisions regarding "with whom" to participate and when to start or how much time to spend on are estimated to investigate the correlations between "with whom" and the start time / duration decisions. Data collected by a seven-day activity diary survey are used for the model developments. Findings suggest that the social context has a relevant role in activity scheduling processes. For example, the investigations indicate that it is "with whom" we socialize what influences the social activity scheduling processes more than the travel time or the distances to social travel. Overall, and additionally to the theoretical understanding of the questions posed to investigate in this paper, the models serve as an empirical support for agent-based microsimulation models that could incorporate the role of social networks in activity scheduling attributes.
Abstract The paper presents a modeling framework for dynamic activity scheduling. The modeling fr... more Abstract The paper presents a modeling framework for dynamic activity scheduling. The modeling framework considers random utility maximization (RUM) assumption for its components in order to capture the joint activity type, location and continuous time expenditure choice tradeoffs over the course of the day. The dynamics of activity scheduling process are modeled by considering the history of activity participation as well as changes in time budget availability over the day.
ABSTRACT Any operational activity-based travel demand model can be divided into two major compone... more ABSTRACT Any operational activity-based travel demand model can be divided into two major components: activity generation and activity scheduling. Although considerable progress in behavioural theory and modelling techniques has been achieved for the activity scheduling component, activity generation in many ways is an overlooked or under researched area. This thesis concentrates on this critical issue from the theoretical perspective as well as empirical model development.
Abstract Transportation supply (transportation system capacity/performance) and urban form define... more Abstract Transportation supply (transportation system capacity/performance) and urban form define the opportunities and constraints operating on mode choice preferences of urban residents. We make use of the Transportation Tomorrow Surveys (TTS), which are household travel surveys conducted in the Greater Toronto and Hamilton Area (GTHA) in 1996, 2001 and 2006.
Abstract This paper presents an econometric modelling technique for a joint trivariate discreteco... more Abstract This paper presents an econometric modelling technique for a joint trivariate discretecontinuous-continuous decision structure. The model formulation exploits successive variable transformation technique (Lee's transformation) to derive likelihood function based on a general error structure. The derived likelihood function is of closed form and estimable by the conventional maximum likelihood estimation technique.
Determining the duration of activity episodes is one of the most important elements of the activi... more Determining the duration of activity episodes is one of the most important elements of the activity scheduling process. The concept of activity scheduling is centered upon the accommodation of different durations (corresponding to activities) within a modelling time frame (daily or weekly). The main philosophy of activity-based travel demand models is to model activities, not travel/trips per se, where travel/trips are emergent activities resulting from the activity participation process (Hägerstrand, 1970).
This paper presents an econometric model for the behaviour of carsharing users. The econometric m... more This paper presents an econometric model for the behaviour of carsharing users. The econometric model is developed to jointly forecast membership duration, the decision to become an active member in a particular month, and the frequency of monthly usage of active members. The model is estimated using the membership directory and monthly transaction data of a carsharing program,'Communauto Inc.', based in Montréal, Canada.
ABSTRACT This paper uses a series of nested logit models to investigate recent mover preferences ... more ABSTRACT This paper uses a series of nested logit models to investigate recent mover preferences for location choice and home type. A comparison of alternative model specifications illuminate the nature of purchase, recognizing location attributes as well as home size and cost.
Although activity-based approach to travel demand modelling was introduced three decades ago, the... more Although activity-based approach to travel demand modelling was introduced three decades ago, the conventional trip-based models are still in use for practical policy investigation in almost everywhere with very few exceptions. The main reason of such failure is the lack of comprehensive modelling framework with consistent behavioural assumptions that can completely replace well-structure trip-based four-stage model.
Cities are the powerhouses of economic growth for any country. According to Bartone et. al.(1994)... more Cities are the powerhouses of economic growth for any country. According to Bartone et. al.(1994), around eighty percent of GDP growth in developing countries is expected to come from cities. For the purpose of economic activities, it is imperative to facilitate movements. Transportation system provides the way for movements and medium for reaching destinations. Inadequate transportation system hampers economic activities and creates hindrances for development.
Traditionally, the parking choice/option is considered to be an important factor in only in the m... more Traditionally, the parking choice/option is considered to be an important factor in only in the mode choice component of a four-stage travel demand modelling system. However, travel demand modelling has been undergoing a paradigm shift from the traditional trip-based approach to an activity-based approach. The activity-based approach is intended to capture the influences of different policy variables at various stages of activity-travel decision making processes.
Ttravel for shopping activities has been one of the aspects of travel behavior to garner substant... more Ttravel for shopping activities has been one of the aspects of travel behavior to garner substantial attention in recent years (Bhat, 1996). Shopping is an essential aspect of our day to day lives as it is necessary in order to fulfill numerous biological (ie food) and other needs (eg clothing, etc.) in addition to being, for many, a leisure or social activity. Despite the rise of online shopping (Mokhtarian, 2004; Farag et al, 2006), shopping continues for the most part to be carried out away from home. As a result, shopping activities induce travel.
Activity-based approaches to travel demand modeling are increasingly moving from theoretical to o... more Activity-based approaches to travel demand modeling are increasingly moving from theoretical to operational models. Agent-based microsimulation models are a promising approach as they explicitly conceive travel as an emergent phenomenon from people's activity characteristics and, more explicitly, from their activity-scheduling processes. Activityscheduling processes are influenced by individuals' characteristics as well as by the people with whom they interact.
Abstract The paper presents an econometric model for departure time choice modelling. The propose... more Abstract The paper presents an econometric model for departure time choice modelling. The proposed model is a discrete choice model with latent choice sets. As per the formulation of the mode, the model falls in the general category of Generalized Extreme Value (GEV) models with choice set formation, which is also known as a Generalized Logit (GenL) model. However, the proposed modelling framework uses a scale parameterization approach to capture heteroskedasticity in departure time choices.
Cultural conflict and contestation is semiotically encoded in the built environment and provides ... more Cultural conflict and contestation is semiotically encoded in the built environment and provides material evidence that the public space and its spatial relations are a cultural production of these struggles (Low, 2000). The public space of Dhaka1 is no exception and has been as much sites of contestation as of negotiation and mediation.
ABSTRACT: Transportation serves as channel for economic development of a country. Development of ... more ABSTRACT: Transportation serves as channel for economic development of a country. Development of transportation facilities involve huge amount of resources and time. Also, in most the cases transportation investment are irreversible. To satisfy the future demand and maximize the benefit of investment in this sector, elaborate planning is deemed necessary. One of the major tasks of planning process is to assess future demand and comprehend the impacts of alternative decisions.
Throughout history, built spaces have been as much sites of contestation as of negotiation and me... more Throughout history, built spaces have been as much sites of contestation as of negotiation and mediation (De Meulder and Shannon, 2007). Public spaces of Dhaka are no exception and represent sites of power, identity and belief backed by a prolonged struggle and the negotiated juxtaposition of public and sacred spaces.
This paper presents an econometric modelling framework for activity-agenda formation. The activit... more This paper presents an econometric modelling framework for activity-agenda formation. The activity-agenda is referred to the collection of different types of activities that are to be scheduled within a specific time period (time budget). The concept of activity utility is used to model frequencies of all individual activity types under consideration within a specific time budget constraint. Contrary to univariate modelling approach for individual activity types separately, this approach deals with all activity types together in a unified econometric modelling framework. The specification of the model also ensures the scope for unplanned (or not defined a priori) activities within time budget. Kuhn-Tucker optimality condition is used to ensure the probability of having zero frequency of any specific activity type. Each individual activity-specific utility has two components: baseline utility and additional utility. The logarithmic function of additional utility ensures the satiation effect with increasing frequency. The heterogeneity in activity behaviour is also considered by incorporating error correlation in baseline utility. Data from the 2002-2003 CHASE survey, collected in Toronto are used to test the model specifications. Application of this modelling framework in an activity-based travel demand model will greatly enhance behavioural validity as well as sensitivity to subtle transportation policies of travel demand models.
The paper describes a comprehensive frequency and time allocation modelling system for shopping a... more The paper describes a comprehensive frequency and time allocation modelling system for shopping activities. The modelling system is person-based but explicitly considers fixed and random household effects. It has three components: a weekly shopping frequency model, a daily shopping frequency model, and a time allocation model for individual shopping episodes. The frequency models consider activity generation as a latent response, the propensity to participate in shopping activities. This latent response is modelled using an ordinal response model. Both the weekly and daily frequency models are multilevel ordinal logit models, where the household is the highest level and the individual person is the lowest level. The multilevel ordinal logit models incorporate household level influences on an individual's shopping behaviour in term of fixed effects and a random intercept. The time allocation models are hazard duration models that consider household-level random heterogeneity. The entire modelling system is sequential from the weekly frequency component to the time allocation component. The outputs of the earlier components enter as inputs to the later components: weekly frequency is the input to the daily frequency model; weekly and daily frequencies are input to the time allocation model. The system is designed to overcome the deficiencies of household-level information in the personallevel activity diary data that are used to develop the model. Khandker M. Nurul Habib and Eric J. Miller
This paper presents four sets of econometric models for time use decisions (durations and start t... more This paper presents four sets of econometric models for time use decisions (durations and start times) regarding the basic, regular and committed components (skeleton) of workers' daily life: gap before work, work, gap after work and night sleep. Then the paper compares two types of models for each component: multilevel linear model and continuous time hazard models. The multilevel models consider three-level random effects (temporal, personal and household) and the hazard models consider individual-based unobserved heterogeneity. Based on performance in fitting observed data, hazard models are selected for the first three components and a multilevel model is selected for the last component. For parametric hazard models, the Gompertz distribution shows promising performance in fitting activity data. The models are estimated by using 2002-2003 Toronto CHASE data. Khandker M. Nurul Habib and Eric J. Miller
Transportation Research Record: Journal of the Transportation Research Board, 2008
Activity-based approaches to travel demand modeling are increasingly moving from theoretical to o... more Activity-based approaches to travel demand modeling are increasingly moving from theoretical to operational models. In this context, agent-based micro-simulation models are a promising approach since they explicitly conceive travel as an emergent phenomenon from peoples' activity characteristics, and more explicitly, from their activity scheduling processes. Behaviorally, activity-scheduling processes are influenced not only by individuals' characteristics, but also by the other people with whom they interact. Thus, the activity scheduling process has an intrinsic social context. Using social activities as a case study, the objective of this paper is to empirically investigate the relationship between the social context (measured by with whom the respondents interacted) and two key aspects of activity scheduling: start time and duration. Econometric models of the combined decisions regarding "with whom" to participate and when to start or how much time to spend on are estimated to investigate the correlations between "with whom" and the start time / duration decisions. Data collected by a seven-day activity diary survey are used for the model developments. Findings suggest that the social context has a relevant role in activity scheduling processes. For example, the investigations indicate that it is "with whom" we socialize what influences the social activity scheduling processes more than the travel time or the distances to social travel. Overall, and additionally to the theoretical understanding of the questions posed to investigate in this paper, the models serve as an empirical support for agent-based microsimulation models that could incorporate the role of social networks in activity scheduling attributes.
Abstract The paper presents a modeling framework for dynamic activity scheduling. The modeling fr... more Abstract The paper presents a modeling framework for dynamic activity scheduling. The modeling framework considers random utility maximization (RUM) assumption for its components in order to capture the joint activity type, location and continuous time expenditure choice tradeoffs over the course of the day. The dynamics of activity scheduling process are modeled by considering the history of activity participation as well as changes in time budget availability over the day.
ABSTRACT Any operational activity-based travel demand model can be divided into two major compone... more ABSTRACT Any operational activity-based travel demand model can be divided into two major components: activity generation and activity scheduling. Although considerable progress in behavioural theory and modelling techniques has been achieved for the activity scheduling component, activity generation in many ways is an overlooked or under researched area. This thesis concentrates on this critical issue from the theoretical perspective as well as empirical model development.
Abstract Transportation supply (transportation system capacity/performance) and urban form define... more Abstract Transportation supply (transportation system capacity/performance) and urban form define the opportunities and constraints operating on mode choice preferences of urban residents. We make use of the Transportation Tomorrow Surveys (TTS), which are household travel surveys conducted in the Greater Toronto and Hamilton Area (GTHA) in 1996, 2001 and 2006.
Abstract This paper presents an econometric modelling technique for a joint trivariate discreteco... more Abstract This paper presents an econometric modelling technique for a joint trivariate discretecontinuous-continuous decision structure. The model formulation exploits successive variable transformation technique (Lee's transformation) to derive likelihood function based on a general error structure. The derived likelihood function is of closed form and estimable by the conventional maximum likelihood estimation technique.
Determining the duration of activity episodes is one of the most important elements of the activi... more Determining the duration of activity episodes is one of the most important elements of the activity scheduling process. The concept of activity scheduling is centered upon the accommodation of different durations (corresponding to activities) within a modelling time frame (daily or weekly). The main philosophy of activity-based travel demand models is to model activities, not travel/trips per se, where travel/trips are emergent activities resulting from the activity participation process (Hägerstrand, 1970).
This paper presents an econometric model for the behaviour of carsharing users. The econometric m... more This paper presents an econometric model for the behaviour of carsharing users. The econometric model is developed to jointly forecast membership duration, the decision to become an active member in a particular month, and the frequency of monthly usage of active members. The model is estimated using the membership directory and monthly transaction data of a carsharing program,'Communauto Inc.', based in Montréal, Canada.
ABSTRACT This paper uses a series of nested logit models to investigate recent mover preferences ... more ABSTRACT This paper uses a series of nested logit models to investigate recent mover preferences for location choice and home type. A comparison of alternative model specifications illuminate the nature of purchase, recognizing location attributes as well as home size and cost.
Although activity-based approach to travel demand modelling was introduced three decades ago, the... more Although activity-based approach to travel demand modelling was introduced three decades ago, the conventional trip-based models are still in use for practical policy investigation in almost everywhere with very few exceptions. The main reason of such failure is the lack of comprehensive modelling framework with consistent behavioural assumptions that can completely replace well-structure trip-based four-stage model.
Cities are the powerhouses of economic growth for any country. According to Bartone et. al.(1994)... more Cities are the powerhouses of economic growth for any country. According to Bartone et. al.(1994), around eighty percent of GDP growth in developing countries is expected to come from cities. For the purpose of economic activities, it is imperative to facilitate movements. Transportation system provides the way for movements and medium for reaching destinations. Inadequate transportation system hampers economic activities and creates hindrances for development.
Traditionally, the parking choice/option is considered to be an important factor in only in the m... more Traditionally, the parking choice/option is considered to be an important factor in only in the mode choice component of a four-stage travel demand modelling system. However, travel demand modelling has been undergoing a paradigm shift from the traditional trip-based approach to an activity-based approach. The activity-based approach is intended to capture the influences of different policy variables at various stages of activity-travel decision making processes.
Ttravel for shopping activities has been one of the aspects of travel behavior to garner substant... more Ttravel for shopping activities has been one of the aspects of travel behavior to garner substantial attention in recent years (Bhat, 1996). Shopping is an essential aspect of our day to day lives as it is necessary in order to fulfill numerous biological (ie food) and other needs (eg clothing, etc.) in addition to being, for many, a leisure or social activity. Despite the rise of online shopping (Mokhtarian, 2004; Farag et al, 2006), shopping continues for the most part to be carried out away from home. As a result, shopping activities induce travel.
Activity-based approaches to travel demand modeling are increasingly moving from theoretical to o... more Activity-based approaches to travel demand modeling are increasingly moving from theoretical to operational models. Agent-based microsimulation models are a promising approach as they explicitly conceive travel as an emergent phenomenon from people's activity characteristics and, more explicitly, from their activity-scheduling processes. Activityscheduling processes are influenced by individuals' characteristics as well as by the people with whom they interact.
Abstract The paper presents an econometric model for departure time choice modelling. The propose... more Abstract The paper presents an econometric model for departure time choice modelling. The proposed model is a discrete choice model with latent choice sets. As per the formulation of the mode, the model falls in the general category of Generalized Extreme Value (GEV) models with choice set formation, which is also known as a Generalized Logit (GenL) model. However, the proposed modelling framework uses a scale parameterization approach to capture heteroskedasticity in departure time choices.
Cultural conflict and contestation is semiotically encoded in the built environment and provides ... more Cultural conflict and contestation is semiotically encoded in the built environment and provides material evidence that the public space and its spatial relations are a cultural production of these struggles (Low, 2000). The public space of Dhaka1 is no exception and has been as much sites of contestation as of negotiation and mediation.
ABSTRACT: Transportation serves as channel for economic development of a country. Development of ... more ABSTRACT: Transportation serves as channel for economic development of a country. Development of transportation facilities involve huge amount of resources and time. Also, in most the cases transportation investment are irreversible. To satisfy the future demand and maximize the benefit of investment in this sector, elaborate planning is deemed necessary. One of the major tasks of planning process is to assess future demand and comprehend the impacts of alternative decisions.
Throughout history, built spaces have been as much sites of contestation as of negotiation and me... more Throughout history, built spaces have been as much sites of contestation as of negotiation and mediation (De Meulder and Shannon, 2007). Public spaces of Dhaka are no exception and represent sites of power, identity and belief backed by a prolonged struggle and the negotiated juxtaposition of public and sacred spaces.
This paper presents an econometric modelling framework for activity-agenda formation. The activit... more This paper presents an econometric modelling framework for activity-agenda formation. The activity-agenda is referred to the collection of different types of activities that are to be scheduled within a specific time period (time budget). The concept of activity utility is used to model frequencies of all individual activity types under consideration within a specific time budget constraint. Contrary to univariate modelling approach for individual activity types separately, this approach deals with all activity types together in a unified econometric modelling framework. The specification of the model also ensures the scope for unplanned (or not defined a priori) activities within time budget. Kuhn-Tucker optimality condition is used to ensure the probability of having zero frequency of any specific activity type. Each individual activity-specific utility has two components: baseline utility and additional utility. The logarithmic function of additional utility ensures the satiation effect with increasing frequency. The heterogeneity in activity behaviour is also considered by incorporating error correlation in baseline utility. Data from the 2002-2003 CHASE survey, collected in Toronto are used to test the model specifications. Application of this modelling framework in an activity-based travel demand model will greatly enhance behavioural validity as well as sensitivity to subtle transportation policies of travel demand models.
The paper describes a comprehensive frequency and time allocation modelling system for shopping a... more The paper describes a comprehensive frequency and time allocation modelling system for shopping activities. The modelling system is person-based but explicitly considers fixed and random household effects. It has three components: a weekly shopping frequency model, a daily shopping frequency model, and a time allocation model for individual shopping episodes. The frequency models consider activity generation as a latent response, the propensity to participate in shopping activities. This latent response is modelled using an ordinal response model. Both the weekly and daily frequency models are multilevel ordinal logit models, where the household is the highest level and the individual person is the lowest level. The multilevel ordinal logit models incorporate household level influences on an individual's shopping behaviour in term of fixed effects and a random intercept. The time allocation models are hazard duration models that consider household-level random heterogeneity. The entire modelling system is sequential from the weekly frequency component to the time allocation component. The outputs of the earlier components enter as inputs to the later components: weekly frequency is the input to the daily frequency model; weekly and daily frequencies are input to the time allocation model. The system is designed to overcome the deficiencies of household-level information in the personallevel activity diary data that are used to develop the model. Khandker M. Nurul Habib and Eric J. Miller
This paper presents four sets of econometric models for time use decisions (durations and start t... more This paper presents four sets of econometric models for time use decisions (durations and start times) regarding the basic, regular and committed components (skeleton) of workers' daily life: gap before work, work, gap after work and night sleep. Then the paper compares two types of models for each component: multilevel linear model and continuous time hazard models. The multilevel models consider three-level random effects (temporal, personal and household) and the hazard models consider individual-based unobserved heterogeneity. Based on performance in fitting observed data, hazard models are selected for the first three components and a multilevel model is selected for the last component. For parametric hazard models, the Gompertz distribution shows promising performance in fitting activity data. The models are estimated by using 2002-2003 Toronto CHASE data. Khandker M. Nurul Habib and Eric J. Miller
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Papers by Khandker Nurul Habib