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This paper presents an analysis of people's time use patterns, incorporating the mediating role of ICT and personal networks on their daily activity-travel patterns, explicitly addressing the issue of activity fragmentation for social-based episodes. Implementing a seven-day time use survey, which includes temporal, spatial, and social characteristics for each activity, and using a theoretical framework based on current theory, a structural equation model was estimated to study these relationships. The results suggest a positive effect of ICT episodes on social activity interaction, activity fragmentation, and out-of-home social allocated time. We also found that ICTs encourage social trip generation only indirectly. Finally, those who had a social network physically close showed higher levels of fragmentation in their social episodes and less out-of-home social activity time. These results add evidence to this research stream, enhancing, and further clarifying ICT's role in people's daily activity behavior. [ABSTRACT FROM AUTHOR]

In the context of an increasing interest in understanding travel for non-mandatory activities, such as recreation and socializing, this work focuses on studying the relationships between activity participation, social networks, and expenditures in daily travel patterns associated with leisure activities in order to understand people's strategies for performing activities in daily life. Using a 7-day time use diary from a resident sample of Concepción, Chile, along with information about people's socio-demography, social network and expenditure behavior, structural equations models were estimated to study the role of social networks on people's space–time and monetary patterns. The results suggest a positive relationship between people's interaction with their social networks, their expenditure levels, and their space–time activity patterns. The analysis adds empirical evidence towards a better understanding of people's decision-making processes by using a time use and a social networks approach. The model results reveal that out-of-home leisure time has a strong impact on the interactions with alters and monetary expenditures. In this context, "with whom" and how much time someone spends doing a specific activity act as key intermediary dimensions to explain leisure activity participation and travel behavior. [ABSTRACT FROM AUTHOR]

Abstract Social networks have attracted attention in different fields of research in recent years and choice modellers have engaged with their analysis by looking at the role that social networks play in shaping decisions across a variety of contexts. The incorporation of the social dimension in choice models creates the need for understanding how social networks evolve over time and in particular which social contacts (alters) are retained over time by an individual (ego). Existing work fails to capture the full extent of ego-level and ego-alter level heterogeneity in these processes. We propose the use of a hybrid model framework which is based on the notion of latent strength of relationship. The resulting model allows for heterogeneity in the latent strength both across individuals and across their different relationships. In addition, we allow for heterogeneity not linked to the latent strength concept. We demonstrate the benefits of the approach using data from Chile, showing the presence of extensive variations in retention of social contacts and in strength of relationship both at the ego and ego-alter level, only some of which can be linked to observed characteristics. [ABSTRACT FROM AUTHOR]

With the interest on understanding and modeling the role of transport on social networks, the objective of this research is to study social network dynamics by explicitly collecting and modeling data from people’s personal networks in two points of time. Using data collected in a two-year panel in Concepción, Chile, a multilevel model highlights the role of respondents’ characteristics and social contact attributes in personal network dynamics. At the respondents’ level, the results highlight the relevance of important life events and material conditions, such as income and car ownership. At the level of the social contacts, the results highlight how tie maintenance is influenced by aspects such as kinship, emotional closeness, monetary support, sex and income similarity, neighboring, and high frequency of face-to-face and telephone interactions. Despite some challenges and limitations, this research remarks the feasibility of collecting personal network dynamics, and its relevance to understand and inform social activity-travel models. [ABSTRACT FROM AUTHOR]

The recent interest in the role of transport in social interactions has been partly motivated by the hope of achieving a better understanding of the role that transport plays in network capital, or the resources that people can gather from their social networks. Despite the relevancy of this question for policy, little empirical work has been done to elucidate this relationship. This paper illustrates a method of data collection and analysis, using the social networks approach to assess the role of transport in social support, both emotional and material. The personal networks of two neighbourhoods in Concepcion, Chile, with different income levels, are compared, focusing on the role of car ownership in network capital, and the relevance of the time and space characteristics of social contacts. The results suggest that having a car at home does not lead to homogeneous access to network capital, which depends heavily on the kind of social resource studied and the income context (neighbourhood) in which the individuals are embedded. The findings also underscore the need to treat social capital as a truly multidimensional concept and the usefulness of the personal networks approach for assessing these complex relationships. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a social activity-travel generation model, which explicitly incorporates the individual’s social dimension through the concept of personal networks, modeling the multilevel structure of social relations defined by these networks. The objective of the analysis is to study the relevance of the social dimension as a source of explanation of social activity-travel generation behavior between an individual and each relevant person of their social life. The paper uses a disaggregated perspective of personal networks, explicitly incorporating the characteristics of each network member as well as the characteristics of the overall social structure. Using an ordinal multilevel specification that accounts for the social network in which individuals are embedded, four dimensions are studied: personal characteristics, “with whom” activities are performed, social network composition and structure, and ICT (information and communication technology) interaction. The results show that a proper and complete understanding of social activity generation requires going beyond the individualistic paradigm, explicitly incorporating the role of the social dimension in the study of this decision-making process. [Copyright &y& Elsevier]

This paper explores the relationship between travel behaviour, ICT use and social networks. Specifically, we outline a theory of social action that can inform how ICTs relates to social activity travel and explore the efficacy of this theory in an empirical setting. We begin by outlining two factors that influence the propensity to travel: an individual's will to initiate events with members of one's social network, referred to as agency, and the social accessibility of network members themselves. Social accessibility defines a series of practical constraints for social-activity travel and agency defines the extent to which an individual will actively work within these constraints to maintain their social network. The theoretical section first unpacks these concepts while embedding them in the research literature, finishing with an operationalisation of agency and social accessibility. Using this theory, the empirical section investigates the relationship between agency, social accessibility, and factors associated with both the respondents and their personal networks. More specifically, we examine how agency levels of interaction are related to differences in demographics, global measures of network structure and composition, and measures of media use, particularly of Internet and telephone. We conclude that individuals who are proximate or more active are more likely to maintain reciprocal relationships, and that more distant or infrequent ties require greater maintenance on the individual's part. We believe that studies of activity-travel and ICTs will benefit from a theoretical lens that articulates some of the transformative effects of ICTs on travel vis-à-vis its effects on social life. Social accessibility and agency can help focus that lens thereby enabling researchers to make potentially more elaborate and realistic models that move beyond the spatial and temporal dimensions into social dimensions. [ABSTRACT FROM AUTHOR]

This paper presents a data collection effort designed to incorporate the social dimension in social activity-travel behavior by explicitly studying the link between individuals' social activities and their social networks. The main hypothesis of the data collection effort is that individuals' travel behavior is conditional upon their social networks; that is, a key cause of travel behavior is the social dimension represented by social networks. With this hypothesis in mind, and using survey and interview instruments, the respondents' social networks are collected using an egocentric approach that is constituted by the interplay between their individual social structures and their social activity behavior. More explicitly, individuals' networks are a context within which to elicit social activity-travel generation, spatial distribution, and information communication and technology use. The resultant dataset links aspects, in novel ways, that have been rarely studied together, and provides a sound base of theory and method to study and potentially give new insights about social activity-travel behavior. [ABSTRACT FROM AUTHOR]

We describe an interview-based data-collection procedure for social network analysis designed to aid gathering information about the people known by a respondent and reduce problems with data integrity and respondent burden. This procedure, a participant-aided network diagram (sociogram), is an extension of traditional name generators. Although such a diagram can be produced through computer-assisted programs for interviewing (CAPIs) and low technology (i.e., paper), we demonstrate both practical and methodological reasons for keeping high technology in the lab and low technology in the field. We provide some general heuristics that can reduce the time needed to complete a name generator. We present findings from our Connected Lives field study to illustrate this procedure and compare to an alternative method for gathering network data. [ABSTRACT FROM AUTHOR]

The development of sustainable transport and mobility systems for the future will not only need more efficient, less contaminating, and technologically enhanced systems, information, and infrastructures; it will also require a transition to new forms of living and modification of contemporary forms of mobility and immobility. This challenge will undoubtedly require an understanding of past and present modes of living in order to disentangle the complexity of contemporary life and pinpoint the implications of new forms of sustainable mobility. Given that new systems, information, materialities, and infrastructures affect people differently, it is vital that preparations be made for the potentially uneven implications of introducing new mobility assemblages, particularly for countries in the global South where sustainability in transport and mobility systems are crucial to overcoming persistent inequalities. An important step in this direction is to understand the current mobility strategies that people employ on a daily basis. This paper addresses these mobility strategies through the lenses of ethnography, time use, and social networks. It does so by identifying new dimensions revealed by the different methods which together present the true diversity of mobility strategies. A case study based on research carried out in Concepción, Chile, illustrates how these tools are combined to reveal the complex decision-making involved in contemporary everyday life. The paper recognizes limitations in terms of data gathering tools, timings, epistemologies, languages, and forms of representation of our work, and challenging proposals for future research are put forward. [ABSTRACT FROM AUTHOR]

An understanding of activity choices and duration is a key requirement for better policy making, in transport and beyond. Previous studies have failed to make the important link with individuals’ social context. In this paper, the Multiple Discrete-Continuous Nested Extreme Value (MDCNEV) model is applied to the choice of activity type and duration over the course of two days, using data from the Chilean city of Concepción. In common with other studies, heterogeneity across decision makers is accommodated in the model by analysing the impact of different socio-demographic, mobility and residential location variables on both the activity choice and the time allocation decision. In addition, different social network and social capital measures are found to be significantly correlated with the choice and duration of different activities, and we show how these relationships seem to differ from the effects of socio-demographic variables. Finally, we perform a forecasting exercise using the MDCNEV model, highlighting the differences in substitution patterns from a standard MDCEV model. [ABSTRACT FROM AUTHOR]

Abstract: Acknowledging the relevance of social networks on (social) travel behaviour, the objective of this paper is to comparatively study the distance patterns between the home locations of social contacts. Analyses are based on five recent collections of personal network data from four countries: Canada, Switzerland, the Netherlands, and Chile. Multilevel models, which explicitly account for the hierarchical structure of the data sets, are used to study the role of explanatory variables to understand the distance patterns of social contacts. Modelling results suggest that alters’ characteristics (such as type of relationship, emotional closeness, and duration of the relationship) as well as personal network composition (alters with a certain relationship to the ego) constitute stronger predictors than an ego’s socio-demographic information across these countries. In addition, comparative analyses suggest differences between countries on relevant key variables such as an ego’s income and the ego–alter tie strength. [Copyright &y& Elsevier]

Social interaction patterns are relevant to explain (social) travel behavior. As such, the objective of this paper is to comparatively study the factors that influence social interaction frequency among social network members with different communication modes. Based on data from seven surveys on social networks, this analysis seeks to shed some light on (i) the similarities and differences in social interaction frequency patterns, (ii) the relation of personal and network characteristics with observed patterns, and (iii) the extent to which these associations are consistent across contexts, in terms of effect direction and magnitude. A multilevel-multivariate lognormal hurdle model is used to jointly analyze social interaction frequency patterns across all datasets. Level 1 includes information on ego-alter dyad characteristics, level 2 includes ego-level socio-demographic and aggregate social network characteristics, while level 3 includes information specific to each context where data was collected. In line with network capital theory, results show the existence of very consistent associations between social interaction frequency and some network and dyad characteristics such as network size, ego-alter distance, and emotional closeness, which showed some degree of generality irrespective of context. Building up on previous research, results also suggest that the effect of a higher transport cost-to-earnings ratio is more likely to manifest in the tie-formation phase, in such a way that the geographical spread of the network will tend to be smaller, but conditional on such a network distribution, the cost-to-earnings ratio effect becomes negligible. For other variables such as education level, gender and relationship type, effect patterns were less clear, which might be explained by socio-economic, and other contextual factors, as well as methodological differences across studies. The model presented here can provide average levels of demand for social interactions, which bounded by the geographical distribution of networks, can be used to further understand travel demand in urban environments and transportation systems at the local or regional level. [ABSTRACT FROM AUTHOR]