Juan Antonio Carrasco

Associate Professor

Transportation Section, Department of Civil Engineering, Faculty of Engineering, Universidad de Concepción

 

Telephone (Office): +56 41 220-3603
Fax: +56 41 220-7089
Email: j.carrasco [at] udec [dot] cl
Address:

Department of Civil Engineering,
Faculty of Engineering,
Universidad de Concepción
P.O. Box 160-C,
Concepción, Chile

 

 

 

Resume (adobe acrobat document)

Education

Research interests

Research projects, grants, and contracts

Publications

Teaching

 

 

EDUCATION

 

Doctor of Philosophy, Transport Engineering and Planning

University of Toronto, Department of Civil Engineering, Transportation Engineering and Planning, 2006

Thesis: Social Activity-Travel Behaviour: A Personal Networks Approach

 [Eric Pas Dissertation Prize (Honourable Mention), awarded by the International Association for Travel Behaviour Research to the best doctoral dissertations on travel behaviour research in the year 2006] (Supervisor: Eric J. Miller, Co-supervisor: Barry Wellman)

 

Master in Engineering Science, Transport Engineering

Pontificia Universidad Católica de Chile, Departamento de Ingeniería de Transporte, Facultad de Ingeniería, 2001

Thesis: ‘Discrete Choice with Correlated Homoskedastic Alternatives: The Nested Logit Model in Depth’ (Supervisor: Juan de Dios Ortúzar)

 

Industrial Engineer, Diploma in Transport Engineering

Pontificia Universidad Católica de Chile, Departamento de Ingeniería de Transporte, Facultad de Ingeniería, 2001

 

Bachelor of Engineering Science

Pontificia Universidad Católica de Chile, Departamento de Ingeniería de Transporte, Facultad de Ingeniería, 1999

 

 

RESEARCH INTERESTS

 

Social networks and activity-travel behaviour

Social exclusion and accessibility issues

Information and communication technologies (ICTs) and travel behaviour

Integrated land use models

Use and estimation of discrete choice and statistical models applied to travel demand analysis

Relationship between urban form and travel decisions

 

 

RESEARCH PROJECTS, GRANTS AND CONTRACTS

 

“Understanding the relationship between people's mobility and food patterns, and the role of attitudes and social networks,” (2017-2020) Chilean National Fund of Science and Technology, FONDECYT (project No 1171113). Total budget: US $260,000 (PI).

 

“Understanding mobility strategies to perform daily activity-travel in two Chilean cities,” (2014-2017) Chilean National Fund of Science and Technology, FONDECYT (project No 1140519). Total budget: US $80,000 (PI).

 

“Center for Sustainable Urban Development (CEDEUS),” Fondo de Financiamiento de Centros de Excelencia en Investigación (Fund for Advanced Research in Priority Areas, Centers of Excellence FONDAP), Chilean National Commission for Science and Technology, CONICYT (project 15110020). Total budget: US$7,500,000 (PI). www.cedeus.cl More info (in Spanish)

 

“Plataforma Tecnológica para la Gestión Integral del Sistema de Transporte en la Región del Bío Bío,” (Technological Platform for Comprehensive Transport System Management in the Bio Bio Region), Fondo de Innovación Tecnológica de la Region del Biobio (Fund for Technological Innovation, Biobio Region), Innova Biobio (project ibb-11-PCS2-1116). Total budget: US $250,000 (co-PI). More info (in Spanish)

 

TranSENDaNC Transport and Social Exclusion: New Directions and National Comparisons” (2012-2014), Marie Curie Actions - International Research Staff Exchange Scheme (IRSES), FP7-PEOPLE-2011, European Union, with Oxford University and Ghent University (project 294963). Total budget: €88,200 (PI). More info.

 

“Understanding the link between transport and social exclusion in the Chilean context: An assessment through quantitative indicators” (2011-2013) Chilean National Fund of Science and Technology, FONDECYT (project No 1110920). Total budget: US $120,000 (PI). More info.

 

Instituto de Sistemas Complejos de la Ingeniería y Tecnología” (Institute of Complex Systems of Engineering and Technology) (2009-2014), Chilean Research, Science and Technology Council (CONCYT), Programa de Financiamiento Basal para Centros de Excelencia, FBO-16. Direct budget: US $52,000 (researcher member). More info.

 

 “La experiencia urbana cotidiana en Concepción: Una exploración por los usos, imaginarios y redes sociales en el Eje Bicentenario” (The daily urban experience in Concepción: An exploration about the use, images, and social networks in a main avenue in the city) (2009-2011) Proyecto DIUC Ciencias Sociales, 209.173.038-1FI (Internal Social Sciences Research Fund, Universidad de Concepción) (co-PI).

 

“Social networks, mobility, and accessibility: Unravelling the social dimension of travel behaviour in a middle size city” (2007-2010) Chilean National Fund of Science and Technology, FONDECYT (project No 11070075). Total budget: US $60,000 (PI). More info.

 

“Graduate Students' Exchange Program (GSEP) Competition” (2008, 2011, 2017), Canadian Commonwealth Scholarship Program (CCSP) Government of Canada Awards (GCA), and Emerging Leaders in America Program (ELAP), Government of Canada. US $55,000. Exchange program that has financed six graduate students to perform research in Canada for four months as part of joint research with Professor Antonio Páez (McMaster University).

 

 

CURRENT AND RECENT PROFFESIONAL ACTIVITIES

 

Journal Editorial

§   Associate editor Transportation Research Part A: Policy and Practice (current)

§   Associate editor Ingeniería de Transporte, Chilean Society of Transportation Engineers, SOCHITRAN (2007-2010 and current). Co-editor (2011-2013)

§   Editorial Board, Transportation Letters: The International Journal of Transportation Research (current)

§   Editorial Board, Revista Geográfica del Sur (current)

 

Scientific Committees

§   Member, Traveler Behavior and Values Committee, ADB10, Transportation Research Board, National Academy of Sciences, USA (from 2011).

§   Co-chair, Time Use and Activity Patterns Subcommittee, ADB10(3), Transportation Research Board, National Academy of Sciences, USA (from 2014).

§   Member, Telecommunications and Travel Behaviour Committee, ADB20, Transportation Research Board, National Academy of Sciences, USA (from 2009).

§   Member, Social and Economic Factors of Transportation Committee, ADD20, Transportation Research Board, National Academy of Sciences, USA (from 2015).

§   Member, International Steering Committee for Travel Survey Conferences (from 2010)

 

Scientific and Organizing Conference Committees

§   Member, organizing committee, Uneven mobilities: Access to activities, people and places in contemporary cities, organized by the PanAmerican Mobility Network, Santiago de Chile, October 2014.

§   Chair, scientific committee, Workshop on Urban Sustainable Transportation, Santiago de Chile, September 2-4, 2013.

§   Member, scientific committee 16th Congreso Chileno de Ingeniería de Transporte, Santiago de Chile, October 21-24, 2013.

§   Member, convening committee of the workshop series Frontiers in Transportation: Social Interactions, Amsterdam (2007), Toronto (2009, 2011), Munich (2013)

§   Member, international network of researchers Time Use Observatory (TUO)

§   Member, international network of researchers ICT: Mobilizing persons, places and spaces: An International Network on Information and Communication Technologies, Everyday Life and Urban Change. http://www.geo.uu.nl/mobilizingICT/index.php

 

Advisory Committees and Consultancy

§   Consultant Project “Recommendations for the urban transport system in a model city: Talca” (financed by the World Bank, 2011).

§   Member, advisory committee tram project for Concepción (2009).

§   Member, advisory committee of the Chilean National Transportation Policy White Paper. Ministry of Transport of Chile (2013)

 

 

PUBLICATIONS

 

See also: Google Scholar

 

Refereed Publications

 

 Calastri, C., S. Hess, A. Daly, and J.A. Carrasco (2017), “Does the social context help with understanding and predicting the choice of activity type and duration? An application of the Multiple Discrete-Continuous Nested Extreme Value model to activity diary data,” Transportation Research Part A, forthcoming.

 

Chávez, O.*, J.A. Carrasco, and A. Tudela (2017), “Social activity-travel dynamics with core contacts: Evidence from a two-wave personal network data,” Transportation Letters: The International Journal of Transportation Research, forthcoming.

 

López, F., A. Páez, J.A. Carrasco and N. Ruminot* (2017), “Vulnerability of Nodes under Controlled Network Topology and Flow Autocorrelation Conditions,” Journal of Transport Geography, 59, 77-87.

 

Rojas, C., A. Páez, O. Barbosa, and J.A. Carrasco (2016), “Accessibility to Urban Green Spaces in Chilean Cities using Adaptive Thresholds,” Journal of Transport Geography, 57, 227-240.

 

Lucas, K., J. Bates, J. Moore*, and J.A. Carrasco (2016), “Modelling the relationship between travel behaviour and social disadvantage,” Transportation Research Part A, 85, 157-173.

 

Schwanen, T., K. Lucas, N. Akyelken, D. Solsona*, J.A. Carrasco, and T. Neutens, (2015), “Rethinking the links between social exclusion and transport disadvantage through the lens of social capital,” Transportation Research Part A, 74, 123-135.

 

Farber, S., T. Neutens, J.A. Carrasco, and C. Rojas (2014), “Exploration of Social Interaction Potential (SIP) and the spatial distribution of face-to-face social interactions,” Environment and Planning B, doi:10.1068/b120034p.

 

García, C., J.A. Carrasco, and C. Rojas (2014), “El contexto urbano y las interacciones sociales: Dualidad del espacio de actividades de sectores de ingresos altos y bajos, localizados en Concepción, Chile,” Eure¸ 40 (121), 75-99. [The urban context and social interactions: Duality of the activity spaces of high and low income groups, located in Concepción, Chile]. http://www.eure.cl/index.php/eure/article/view/478

 

Kowald, M., P. van den Berg, A. Frei, J.A. Carrasco, T. Arentze, K. Axhausen, D. Mok, H. Timmermans, and B. Wellman (2013), “Distance patterns of personal networks in four countries: A comparative study,” Journal of Transport Geography, http://dx.doi.org/10.1016/j.jtrangeo.2013.06.006. Preprint

 

Whalen, K., A. Páez, and J.A. Carrasco (2013), “Mode choice of university students commuting to school and the role of active travel,” Journal of Transport Geography, 31, 132-142, http://dx.doi.org/10.1016/j.jtrangeo.2013.06.008.

 

Moore, J., J.A. Carrasco, and A. Tudela (2013), “Exploring the links between personal networks, time use, and the spatial distribution of social contacts,” Transportation, 40(4), 773-788. Preprint

 

Carrasco, J.A. and B. Cid-Aguayo (2012), "Network capital, social networks, and travel: An empirical illustration from Concepción, Chile," Environment and Planning A, 44(5), 1066-1084. Preprint

 

Carrasco, J.A. (2011), "Personal network maintenance, face to face interaction, and distance: Studying the role of ICT availability and use," Transportation Research Record: Journal of the Transportation Research Board, 2231, 120-128. Preprint

 

Galdames, C., A. Tudela, and J.A. Carrasco (2011), "Exploring the role of psychological factors on mode choice models using a latent variables approach" Transportation Research Record: Journal of the Transportation Research Board, 2230, 68-74. Preprint

 

Habib, K.N., and J.A. Carrasco (2011), "Investigating the role of social networks in start time and duration of activities: A trivariate simultaneous econometric model," Transportation Research Record: Journal of the Transportation Research Board, 2230, 1-8. Preprint

 

Mok, D., B. Wellman and J.A. Carrasco (2010), "Does distance matter in the age of the Internet?" Urban Studies, 47(13), 2747-2784.Preprint

 

Carrasco, J.A. and E. J. Miller (2009), "The social dimension in action: A multilevel, personal networks model of social activity frequency," Transportation Research Part A, 43(1), 90-104. Preprint

 

M. Roorda, M., J.A. Carrasco, and E.J. Miller (2009), “A joint model of vehicle transactions, activity scheduling, and mode choice”, Transportation Research Part B, 43(2), 217-229. Abstract

 

Carrasco, J.A., E.J. Miller, and B. Wellman, “"How far and with whom do people socialize? Empirical evidence about distance between social network members," Transportation Research Record: Journal of the Transportation Research Board, 2076, 114-122. Preprint

 

Habib. K.N., J.A. Carrasco, and E.J. Miller, "Social context of activity scheduling: Discrete-continuous model of relationship between "with whom" and episode start time and duration," Transportation Research Record: Journal of the Transportation Research Board, 2076, 81-87. Preprint

 

Carrasco, J.A., B. Hogan, B. Wellman, and E. J. Miller (2008), "Agency in social activity and ICT interactions: The role of social networks in time and space," Tijdschrift voor Economische en Sociale Geografie (Journal of Economic & Social Geography), 99(5), 562-583. Preprint

 

Carrasco, J.A., B. Hogan, B. Wellman, and E. J. Miller (2008), "Collecting social network data to study social activity-travel behaviour: An egocentric approach," Environment and Planning B, 35(6), 961-980. Abstract  Preprint

 

Hogan, B., J. A. Carrasco, and B. Wellman (2007), “Visualizing personal networks: Working with participant-aided sociograms”, Field Methods, 19(2) 116-144. Abstract  Preprint

 

Carrasco, J.A. and E. J. Miller (2006), "Exploring the propensity to perform social activities: Social networks approach," Transportation, 33: 463-480. Abstract  Preprint

 

Miller, E.J., M. Roorda, and J.A. Carrasco, (2005), “A Tour-Based Model of Travel Mode Choice”, Transportation, 32: 399-422. Abstract

 

Carrasco J.A. and J. de D. Ortúzar (2002), “A Review and Assessment of the Nested Logit Model”, Transport Reviews 22(2): 197-218. Abstract

 

Peer Reviewed Book Chapters and Published Proceedings

Carrasco, J.A. and K. Lucas (2015), “Measuring attitudes: quantitative and qualitative methods,” Transportation Research Procedia, 11, 165-171.

Carrasco, J.A. (2015), “Personal characteristics, social contacts and transport systems,” Chapter 6 in Social Networks and Travel Behaviour, M. Kowald and K. Axhausen (eds.), UK: Ashgate.

Frei, A., M. Kowald, P. van den Berg, and J.A. Carrasco (2015), “Country specific characteristics matter,” Chapter 5 in Social Networks and Travel Behaviour, M. Kowald and K. Axhausen (eds.), UK: Ashgate.

Carrasco, J.A. (2014), “Transportation Policy of South America,” Encyclopedia of Transportation: Social Science and Policy, M. Garret (eds.), USA: SAGE.

Morency, C. and J.A. Carrasco (2013), “Photo stories of hard-to-model and hard-to-understand travel behavior,” in Chapter 1 in Travel Behaviour Research: Current Foundations, Future Prospect, M. Roorda and E.J. Miller (eds.), USA: Lulu Publishers.

Carrasco, J.A., C. Bustos, and B. Cid-Aguayo (2013), “Affective personal networks versus daily contacts: Analyzing different name generators in a social activity-travel behaviour context,” Chapter 22, p. 407-424, in Transport Survey Methods: Best Practice for Decision Making, J. Zmud, M. Lee-Gosselin, M. Munizaga, and J.A. Carrasco (eds.), London: Emerald Press.

Daly, A. and J.A. Carrasco (2009), "The influence of trip length on marginal time and money values: An alternative explanation," Proceedings IATBR 2006, R. Kitamura Ed. Elsevier.

Wellman, B., B. Hogan, K. Berg, J. Boase, J. A. Carrasco, R. Côté, J. Kayahara, T. Kennedy, and P. Tran (2006), "Connected Lives: The Project," Chapter 8 in The Networked Neighbourhoods, P. Purcell, Ed. Berlin: Springer. Preprint

 

Book Edited

Zmud, J., M. Lee-Gosselin, M. Munizaga, and J.A. Carrasco, eds. (2013), Transport Survey Methods: Best Practice for Decision Making. London: Emerald Press.

Carrasco, J.A., S. Jara-Díaz, and M. Munizaga, eds. (2011), Time Use Observatory. Ed. LOM: Santiago de Chile.

 

Editorial/Special Issue

Carrasco, J.A. and S. Farber (2014), “Selected papers on the study of the social context of travel behavior,” special issue for Transportation Research Part A, 68, 1-2.

Dugundji, E., D. Scott, J.A. Carrasco, and A. Páez (2012), “Urban mobility and social-spatial interaction,” special issue of Environment and Planning A, 44(5), 1011-1015.

Dugundji, E., A. Páez, T. Arentze and J. Walker, with contributions from J.A. Carrasco, F. Marchal, and H. Nakanishi (2011), “Transportation and social interactions,” Guest Editorial, Transportation Research Part A, 45(4), 239-247.

 

Other Peer Reviewed Publications

Tudela, A., R. Daziano, and J.A. Carrasco (2013), “El papel de los factores contextuales, socioeconómicos y sicológicos en la elección de modo: Un estudio de caso de Concepción,” Ingeniería de Transporte, 17(1), 29-35.

De la Fuente, H., C. Rojas, M.J. Salado, J.A. Carrasco, and T. Neutens (2013), “Socio-spatial inequality in education facilities in the Concepción Metropolitan Area (Chile),” Current Urban Studies, 1(4), 117-129, DOI: 10.4236/cus.2013.14013. Webpage.

Roa, H., C. Rojas, J.A. Carrasco, and A. Tudela (2013), “Movilidad urbana e indicadores de exclusión social del sistema de transporte: evidencia en una ciudad intermedia chilena,” Revista Transporte y Territorio, Universidad de Buenos Aires, Nº 8, 72-91. http://www.rtt.filo.uba.ar/numero08.html. Versión pdf

Bustos, C. J.A. Carrasco, C. Rojas, and A. Tudela (2012), “Indicadores del espacio de actividades sociales  de individuos del Gran Concepción utilizando la perspectiva de las redes personales,” Ingeniería de Transporte, 16.

Jara, M. and J.A. Carrasco (2010), "Indicadores de inclusión social, accesibilidad y movilidad: Experiencias desde la perspectiva del sistema de transporte", Ingeniería de Transporte, 14(1), 19-26.

Carrasco, J.A. (2007), "Redes sociales y comportamiento de transporte: Marco teórico y resultados empíricos", Ingeniería de Transporte, 13(1), 11-17.

 

Peer Reviewed Conference Proceedings and Presentations

Calastri, C., S. Hess, A. Daly, A. Pinjari and J.A. Carrasco (2017) “Dealing with discrete continuous activity decisions across multiple days in the presence of day specific constraints and preferences,” 5th International Choice Modelling Conference, Cape Town, April, 3-5, 2017.

Calastri, C., S. Hess, J.A. Carrasco, C. Choudhury and A. Daly (2017) “Keeping social contacts over time: The role of life-course events and latent tie strength,” 5th International Choice Modelling Conference, Cape Town, April, 3-5, 2017.

Tudela, A., C. Durán, J.A. Carrasco and A. Tapia (2017) “Does the design of the environment affect the willingness to transfer between modes?” 5th International Choice Modelling Conference, Cape Town, April, 3-5, 2017.

Calastri, C., S. Hess and J.A. Carrasco (2017), "Incorporating the social dimension in the choice of activity type and duration: an application of the Multiple Discrete-Continuous Extreme Value (MDCEV) model" 96th Annual Transportation Research Board Meeting, Washington, D.C., January 8-12, 2017.

Jirón, P., and J.A. Carrasco (2106), “Interdependence, gender and mobility: Understanding mobility strategies in Concepción, Chile,” 14th T2M Annual Conference, The International Association for the History of Transport, Traffic and Mobility, Mexico City, October 27-29, 2016.

Tudela, A., and J.A. Carrasco (2106), “Obtención de matrices Origen Destino a partir de diagramas de carga,” XIX Congreso Panamericano de Ingeniería de Tránsito, Mexico City, September 28-30, 2016.

Calastri, C., S. Hess and J.A. Carrasco (2016), “Investigating the impact of sociability and social networks on the demand for leisure travel: implications for Chilean transport policy,” ITEA Annual Conference and School on Transportation Economics, Santiago, June 14-17, 2016.

Tapia, A., A. Tudela, and J.A. Carrasco (2016), “Can personality factors in mode choice affect the outcome of the transport investments decision making process? A case study in the Chilean context,” 95th Annual Transportation Research Board Meeting, Washington, D.C., January 10-14, 2016.

Sharmeen, F., O. Chávez, J.A. Carrasco, T. Arentze, and A. Tudela (2016), “Modeling population-wide personal network dynamics using a two wave data collection method and an origin-destination survey,” 95th Annual Transportation Research Board Meeting, Washington, D.C., January 10-14, 2016.

Rojas, C., A. Páez, O. Barbosa, and J.A. Carrasco (2016), “Measuring walking access to urban green spaces: The role of age, gender, and income in two Chilean case studies,” 95th Annual Transportation Research Board Meeting, Washington, D.C., January 10-14, 2016.

Chávez, O., J.A. Carrasco, and A. Tudela (2015), “Un estudio de las dinámicas de redes sociales personales para el estudio de actividades y viajes sociales utilizando fusión de datos en dos cortes temporales,” XVII Congreso Chileno de Ingeniería de Transporte, Concepción, 13-16 October, 2015.

Urrutia, N., A. Tudela, and J.A. Carrasco (2015), “Cobertura espacial, temporal y económica del transporte público en el Gran Concepción: Un estudio basado en indicadores,” XVII Congreso Chileno de Ingeniería de Transporte, Concepción, 13-16 October, 2015.

Tapia, A., A. Tudela, and J.A. Carrasco (2015), “Impacto de los factores contextuales, socioeconómicos y psicológicos sobre la cuantificación de beneficios de un proyecto de transporte,” XVII Congreso Chileno de Ingeniería de Transporte, Concepción, 13-16 October 2015.

Rojas, C., J.A. Carrasco, F. Pérez, G. Araneda, and C. García (2015), “Análisis espacial de redes sociales,” XV Conferencia Iberoamericana de Sistemas de Información Geográfica, Valparaíso, 10-11 de septiembre de 2015.

Bustamante, R., A. Tapia, A. Tudela, and J.A. Carrasco, J.A. (2015) “Does transport have any role on well-being? A Chilean case study” 14th International Conference on Travel Behaviour Research, Windsor, 19-23 July 2015.

Van den Berg, P., and J.A. Carrasco (2015) “Intrapersonal changes in social activity-travel patterns: Linking time use and social network dynamics,” 14th International Conference on Travel Behaviour Research, Windsor, 19-23 July 2015.

Bustamante, R., A. Tapia, A. Tudela, and J.A. Carrasco, J.A. (2015), “Assessing transport disadvantage and transit use through people’s knowledge, experience,  and barriers to activities and modes,” 14th International Conference on Competition and Ownership in Land Passenger Transport (Thredbo 14), Santiago de Chile, 30 August - 3 September 2015.

Chávez, O., J.A. Carrasco, and A. Tudela (2015) “Social activity-travel dynamics with core contacts: Evidence from a two-wave personal network data” 94th Annual Transportation Research Board Meeting, Washington, D.C., January 11-15, 2015.

Carrasco, J.A, D. Sandoval, O. Chávez, and B. Cid-Aguayo (2014) “Spatial and temporal dynamics on personal networks: Some methodological and theoretical challenges to study their embedded social travel behavior” 10th International Conference on Transport Survey Methods¸ Leura, Australia, November 16-21, 2014.

Bustamante, R., S. Baeza, A. Tudela, and J.A. Carrasco (2014) “Measuring social exclusion using a non-normative approach” 10th International Conference on Transport Survey Methods¸ Leura, Australia, November 16-21, 2014.

Carrasco, J.A., A. Tudela, C. Rojas (2014), “A mobility perspective on urban segregation and social exclusión: Evidence from personal networks from four Chilean neighbourhoods,” Uneven mobilities. Access to activities, people and places in contemporary cities, PanAmerican Mobilities Network, Santiago de Chile, October 13-16, 2014.

Tapia, A., A. Tudela, and J.A. Carrasco (2014), “El impacto de variables psicológicas en la estimación y predicción de la demanda. Un estudio de caso en Concepción,” XVIII Congreso Panamericano de Ingeniería de Tránsito, Transporte y Logística, Santander, España, June 11-13, 2014.

Linco, H., J.A. Carrasco, and A. Tudela (2014), “Actividades y viajes sociales en Concepción, Chile: Un estudio comparativo de las características temporales, espaciales y sociales de las redes personales de viajeros de cuatro barrios,” XVIII Congreso Panamericano de Ingeniería de Tránsito, Transporte y Logística, Santander, España, June 11-13, 2014.

Cerda, Z., A. Tudela, J.A. Carrasco, and S. Baeza (2014) “Exclusión social: El conocimiento y experiencia acerca de actividades y las barreras para el desarrollo de éstas,” XVIII Congreso Panamericano de Ingeniería de Tránsito, Transporte y Logística¸ Santander, España, June 11-13, 2014.

Rojas, C., A. Schäfer, F. Aguilera, C. Peyrin, J.A. Carrasco, A. Tudela, T. Neutens (2014), “Accessibility to educational and health facilities in the middle city of Los Angeles, Chile, as an indicator of transport disadvantage,” NECTAR Cluster 6 meeting: Accessibility and Policy Making, Sevilla, February 6-7, 2014.

Tapia, A., V. Sichel, A. Tudela, and J.A. Carrasco (2013), “El impacto de variables de personalidad en la estimación de la demanda: Un estudio de caso en Concepción,” in XVI Congreso Chileno de Ingeniería de Transporte, Santiago de Chile, October 22-25, 2013.

Moore, J., J.A. Carrasco, and A. Tudela (2013), “Exploring the links between personal networks, time use, and the spatial distribution of social contacts,” in 92nd Annual Meeting of the Transportation Research Board, Washington D.C., January 13-17, 2013.

Farber, S., T. Neutens, J.A. Carrasco, and C. Rojas (2013), “Exploration of Social Interaction Potential (SIP) and the Spatial Distribution of Face-to-face Social Interactions,” in 92nd Annual Meeting of the Transportation Research Board, Washington D.C., January 13-17, 2013. Also presented at the 13th International Conference on Travel Behaviour Research, Toronto, 15-20 July 2012.

Lucas, K., J. Bates, J. Moore, and J.A. Carrasco (2013) “Modeling the relationship between tranvel behaviours and social disadvantage,” 45th Annual Universities’ Transport Studies Group (UTSG) Conference, Oxford, UK, January 2-4, 2013.

Schwanen, T., K. Lucas, J.A. Carrasco, T. Neutens, N. Akyelken D. Solsona (2013) “Reconceptualising the links between transport disadvantage and social exclusion,” 45th Annual Universities’ Transport Studies Group (UTSG) Conference, Oxford, UK, January 2-4, 2013.

Martínez, M., C. Rojas, J.A. Carrasco, and A. Codeço (2012), “Indicadores de accesibilidad para la evaluación territorial de la red por carretera desde una perspectiva geográfica,” PANAM 2012: XVII Congreso Panamericano de Ingeniería de Tránsito y Transporte y Logística, Santiago de Chile, September 24-27, 2012.

Roa, H., M. Jara, J.A. Carrasco, C. Rojas, and  A. Tudela (2012), “Contexto urbano e indicadores de exclusión social relacionada al sistema de transporte: Evidencia de dos ciudades chilenas,” PANAM 2012: XVII Congreso Panamericano de Ingeniería de Tránsito y Transporte y Logística, Santiago de Chile, September 24-27, 2012.

Tudela, A., R. Daziano, and J.A. Carrasco (2012), “El papel de los factores contextuales, socioeconómicos y psicológicos en la elección de modo: Un estudio de caso en Concepción,” PANAM 2012: XVII Congreso Panamericano de Ingeniería de Tránsito y Transporte y Logística, Santiago de Chile, September 24-27, 2012.

Cerda, Z., A. Tudela, J.A. Carrasco (2012), “On the role of personality when assessing the role of transport on social exclusion,” Fifth International Conference on Traffic and Transport Psychology, Groningen, The Netherlands, August 29-31, 2012.

Kowald, M., P. van den Berg, A. Frei, J.A. Carrasco, T. Arentze, K. Axhausen, D. Mok, H. Timmermans, and B. Wellman (2012), “The Spatiality of Personal Networks in Four Countries: A Comparative Study,” 13th International Conference on Travel Behaviour Research, Toronto, 15-20 July 2012.

Tudela, A., J.A. Carrasco, and R. Daziano (2012), “Personal factors on mode choice: Attitude, affect, social and habit. Measuring and studying their role,” 13th International Conference on Travel Behaviour Research, Toronto, 15-20 July 2012.

Jara, M., J.A. Carrasco, A. Tudela, and C. Rojas (2001), “Indicadores del rol del sistema de transportes en la exclusión social: Metodología y aplicación en el Gran Concepción,” XXXII Congreso Nacional y XVII Internacional de Geografía, Valparaíso, Chile, November 22-25, 2011.

Carrasco. J.A., C. Bustos, and B. Cid-Aguayo (2011), “Affective personal networks versus daily contacts: Analyzing different name generators in an activity-travel behaviour context,” in 9th International Survey Methods Conference, Termas de Puyehue, Chile, November 14-18, 2011.

Bustos, C. J.A. Carrasco, and C. Rojas (2011), “Indicadores del espacio de actividades sociales  de individuos del Gran Concepción utilizando la perspectiva de las redes personales,” in XV Congreso Chileno de Ingeniería de Transporte, Santiago de Chile, October 3-6, 2011.

Carrasco J.A. (2011), “Redes sociales, movilidad espacial y patrones de interaccion: Cuatro barrios de Concepcion, Chile,” in XXVIII Congreso Internacional de la Asociación Latinoamericana de Sociología (ALAS), Recife, September 6-11, 2011.

Tudela, A., K.N. Habib, A. Osman, and J.A. Carrasco (2011), “Incorporating the explicit role of psychological factors on mode choice: A hybrid mode choice model by using data from an innovative psychometric survey,” in International Choice Modelling Conference 2011, Leeds, U.K., July 4-6, 2011.

Carrasco, J.A. (2011), "Personal network maintenance, face to face interaction, and distance: Studying the role of ICT availability and use," in 90th Annual Meeting of the Transportation Research Board, Washington D.C., January 23-27, 2011.

Habib, K.N., and J.A. Carrasco (2011), "Investigating the role of social networks in start time and duration of activities: A trivariate simultaneous econometric model, " in 90th Annual Meeting of the Transportation Research Board, Washington D.C., January 23-27, 2011. A previous version was presented at 12th World Conference on Transport Research, Lisbon, Portugal, July 11-15, 2010.

Galdames, C., A. Tudela, and J.A. Carrasco (2011), "Exploring the role of psychological factors on mode choice models using a latent variables approach" in 90th Annual Meeting of the Transportation Research Board, Washington D.C., January 23-27, 2011.

Céspedes, N., A. Páez and J.A. Carrasco (2010), “Tertiary streets and the strength of autocorrelation using Moran`s Coefficient,” 57th Annual North American Meetings of the Regional Science Association International, Denver, November 11-13, 2010.

Jara, M. and J.A. Carrasco (2010), “Indicadores temporales y espaciales de exclusión social y transporte: Una ilustración empírica,” PANAM 2010: XVI Congreso Panamericano de Ingeniería de Tránsito y Transporte y Logística, Lisbon, Portugal, July 15-18, 2010.

Ruminot, N., A. Páez, and J.A. Carrasco (2010), "Network Topology, Autocorrelation, and Node Vulnerability," in 89th Annual Meeting of the Transportation Research Board, Washington D.C., January 10-14, 2010.

Carrasco, J.A (2009), "Unravelling the social, urban, and time-space context of activity-travel behaviour: Results from a social network data collection experience", 12th International Conference on Travel Behaviour Research, Jaipur, December 13-18, 2009.

Carrasco, J.A and K.N. Habib (2009), "Understanding the social embeddedness of activity-travel participation: The case of frequency and duration of social activities", 12th International Conference on Travel Behaviour Research, Jaipur, December 13-18, 2009.

Jara, M. and J.A. Carrasco (2009), “Indicadores de inclusión, accesibilidad y movilidad espacial: Análisis desde la perspectiva del comportamiento de transporte urbano,” XV Congreso Latinoamericano de Transporte Público y Urbano – CLATPU, Buenos Aires, Argentina, March 31 – April 3, 2009.

Carrasco, J.A., J. Núñez, and K. Inostroza (2008), “Redes sociales y movilidad diaria en el espacio urbano: Marco teórico, datos y métodos de análisis,” XXIX Congreso Nacional y XIV Internacional de Geografía, Temuco, Chile, October 14-17, 2008.

Ruminot, N., A. Páez, and J.A. Carrasco (2008) “Vulnerable nodes in networks: An autocorrelation approach,” 48th Congress of the European Regional Science Association, Liverpool, August 27-31, 2008.

 

Mok, D., B. Wellman and J.A. Carrasco (2008), “Does distance matter in the age of the Internet: Are cities losing their comparative advantage?,103rd Annual Meeting of the American Sociological Association, Boston, August 1-4, 2008. Preprint

 

Carrasco, J.A., E.J. Miller, and B. Wellman, (2008), "How far and with whom do people socialize? Empirical evidence about distance between social network members," in 87th Annual Meeting of the Transportation Research Board, Washington D.C., January 13-17, 2008. A previous version of this paper was presented at the 53rd Annual North American Meetings of the Regional Science Association International, Toronto, November 26-28, 2006.

 

Habib. K.N., J.A. Carrasco, and E.J. Miller (2008), "Social context of activity scheduling: Discrete-continuous model of relationship between "with whom" and episode start time and duration," in 87th Annual Meeting of the Transportation Research Board, Washington D.C., January 13-17, 2008. A previous version of this paper was presented at the XIII Congreso Chileno de Ingeniería de Transporte, Chile, Santiago, October 22-26, 2007.

 

Carrasco, J.A. (2007), "Redes sociales y comportamiento de transporte: Marco teórico y resultados empíricos", in XIII Congreso Chileno de Ingeniería de Transporte, Chile, Santiago, October 22-26, 2007. (Full text available upon request)

 

Carrasco, J.A., D. Mok, and B. Wellman (2007), "Integrating distance, travel, and the mode of contact: The Connected Lives Study", Communities and Technologies 2007, Michigan, June 28-30, 2007. (Full text available upon request)

 

Habib, K.M.N, J.A. Carrasco, and E.J. Miller (2007), "The social dimension of individual’s activity scheduling: How “with whom” influences activity participation", 11th World Conference on Transport Research, Berkeley, June 24-28, 2007.

 

Hogan, B., J.A. Carrasco, and B. Wellman (2007), " Maintaining ties near and far: Agency and social accessibility in personal communities", 102nd Annual Meeting of the American Sociological Association, New York, August 11-14, 2007. A previous version of this paper was presented at the International Sunbelt Social Network Conference XXVII, Corfu Island, Greece, May 1-6, 2007. (Full text available upon request)

 

Carrasco, J.A. and E. J. Miller (2007), "The social dimension in action: A multilevel, personal networks model of social activity frequency," in 86th Annual Meeting of the Transportation Research Board, Washington D.C., January 21-25, 2007. Preprint

 

Carrasco, J.A., E.J. Miller, and B. Wellman, (2006), “Spatial and social networks: The case of travel for social activities”, 11th International Conference on Travel Behaviour Research, Kyoto, August 16-20, 2006. Abstract (Full text available upon request)

 

M. Roorda, M., J.A. Carrasco, and E.J. Miller (2006), “A joint model of vehicle transactions, activity scheduling, and mode choice”, 11th International Conference on Travel Behaviour Research, Kyoto, August 16-20, 2006. Abstract

 

Daly, A. and J.A. Carrasco (2006), “The influence of trip length on marginal time and money values”, 11th International Conference on Travel Behaviour Research, Kyoto, August 16-20, 2006. Abstract

 

Carrasco, J.A., B. Hogan, B. Wellman, and E. J. Miller (2006), "Collecting social network data to study social activity-travel behavior: An egocentered approach," in 85th Annual Meeting of the Transportation Research Board, January 22-26, 2006, Washington D.C. [Also presented at MCRI/GEOIDE Second International Colloquium on the Behavioural Foundations of Integrated Land-use and Transportation Models: Frameworks, Models and Applications, Toronto, June 13-14, 2005; and as an invited paper at the workshop Frontiers in Transportation: Social and Spatial Interactions, Amsterdam, Netherlands, July 2-6, 2005]

 

Carrasco, J.A. and E. J. Miller (2006), "Exploring the propensity to perform social activities: A social networks approach," in 85th Annual Meeting of the Transportation Research Board, January 22-26, 2006, Washington D.C.

 

Carrasco, J.A. and E. J. Miller (2005), "Socialising with people and not places: Modelling social activities explicitly incorporating social networks," in 9th Computers in Urban Planning and Urban Management Conference, London, June 29 - July 1, 2005. (Full text available upon request)

 

Miller, E.J., M. Roorda, and J.A. Carrasco, (2003), “A Tour-Based Model of Travel Mode Choice”, 10th International Conference on Travel Behaviour Research, Lucerne, 10-15 August, 2003. Abstract

 

Carrasco J.A., J de D. Ortúzar, and M. Munizaga (2001), “Una revisión y análisis del modelo Logit Jerárquico”, 8th Chilean Transport Engineering Conference, 8 -12 October 2001, Concepción (in Spanish). Abstract

 

 

TEACHING

 

Universidad de Concepción

Modelos de Demanda de Transporte

Redes de Transporte

Fundamentos de la Ingeniería de Transporte

Planificación de Transporte

Uso de Suelo y Transporte

Métodos de Optimización

Desafíos de la Ingeniería Civil

Seminario de Tesis de Magíster

 

University of Toronto

Probability and Statistics for Civil Engineers

 

 

ABSTRACTS

 

A Review and Assessment of the Nested Logit Model

 

J.A. Carrasco and J. de D. Ortúzar

 

Abstract

 

The popular hierarchical or nested logit model that has been the recent source of heated discussions in the literature is reviewed and critically examined. The fundamental underpinnings of the model are first presented in a concise and easy-to-understand fashion and then used to assess each controversy in turn. Monte Carlo simulation is also used to examine some problems that are not possible to address by just resorting to the theory. The main conclusion is that all the model hypotheses are both essential and unambiguous and should not be ignored for a correct use of the model in practice.

 

 

A Tour-Based Model of Travel Mode Choice

 

E.J. Miller, M. Roorda, and J.A. Carrasco

 

Abstract

 

This paper presents a new tour-based mode choice model. The model is agent-based: both households and individuals are modelled within an object-oriented, microsimulation framework. The model is household-based in that inter-personal household constraints on vehicle usage are modelled, and the auto passenger mode is modelled as a joint decision between the driver and the passenger(s) to ride-share.  Decisions are modelled using a random utility framework. Utility signals are used to communicate preferences among the agents and to make trade-offs among competing demands. Each person is assumed to choose the “best” combination of modes available to execute each tour, subject to auto availability constraints that are determined at the household level. The household’s allocations of resources (i.e., cars to drivers and drivers to ride-sharing passengers) are based on maximizing overall household utility, subject to current household resource levels. The model is activity-based: it is designed to be integrated within a household-based activity scheduling microsimulator.  The model is both chain-based and trip-based.  It is trip-based in that the ultimate output of the model is a chosen, feasible travel mode for each trip in the simulation. These trip modes are, however, determined through a chain-based analysis. A key organizing principle in the model is that if a car is to be used on a tour, then it must be used for the entire chain, since the car must be returned home at the end of the tour. No such constraint, however, exists with respect to other modes such as walk and transit. The paper presents the full conceptual model and an initial empirical prototype.

 

 

A Review and Assessment of the Nested Logit Model

 

J.A. Carrasco and J. de D. Ortúzar

 

Abstract

 

The popular hierarchical or nested logit model that has been the recent source of heated discussions in the literature is reviewed and critically examined. The fundamental underpinnings of the model are first presented in a concise and easy-to-understand fashion and then used to assess each controversy in turn. Monte Carlo simulation is also used to examine some problems that are not possible to address by just resorting to the theory. The main conclusion is that all the model hypotheses are both essential and unambiguous and should not be ignored for a correct use of the model in practice.

 

 

Exploring the propensity to perform social activities: A social networks approach

 

J.A. Carrasco, and E. J. Miller

 

Abstract

 

A conceptual model of social activity-travel behaviour is described, incorporating an activity-scheduling framework which explicitly includes the influence of the individual’s social context. More explicitly, the model develops the concepts of social networks, activities, and social episodes, and defines the individual’s social activity generation and spatial distribution in a context of his/her social networks. Also, empirical findings regarding the influence of social network characteristics on individual’s socialising patterns are discussed. Results suggest that a social networks framework provides interesting insights into the role of physical space, and communication and information technology use. Overall, explicitly incorporating social networks into the activity-travel behaviour modelling framework provides a rich set of insights to understand social activities and the embedded behavioural processes, potentially helping to better understand important issues such as the generation and spatial distribution of activities and travel.

 

 

Collecting social network data to study activity-travel behaviour: An egocentred approach

 

J.A. Carrasco, B. Hogan, B. Wellman, and E. J. Miller

 

Abstract

 

Within the study of activity and travel demand, there has been an increasing interest in the effect of social interactions in activity-travel behaviour, that is, how social networks influence activity-travel decisions. Despite this interest, to the authors’ knowledge, no data collection effort has linked explicitly travel behaviour and social interaction, so far. Moreover, although data collection and modelling techniques have gone very far understanding individual activity-travel decision making processes in time and space, we know very little about the linkages between social and spatial interactions. In a companion paper, we showed a conceptual model of social activity-travel behaviour, that links three elements: the characteristics of individuals, their social networks, and the social activity-travel behaviour that arises in this context.

 

This paper presents the data collection effort designed to partly support that model, including the main research questions and characteristics of the data, the conceptual options taken, the main techniques used, the practical issues and limitations of the method selected, and the expected results.

 

The data was gathered in the East York area of Toronto between June 2004 and March 2005, as part of the “Connected Lives Study”, a broader study composed by surveys, interviews, and observations about people’s communication patters. The study was conducted by the first author in conjunction with sociologists and social workers of the NetLab, part of the Centre of Urban and Community Studies at the University of Toronto, and lead by the sociologist Barry Wellman. The multidisciplinary setting allowed for a rich crossed-fertilisation in data collection techniques, and a broad set of information gathered.

 

Having as a motivation the study of social and spatial interactions, this paper discusses the way social network data was collected, and the link made with activity-travel behaviour pattern data. Social network data is traditionally gathered in two ways: as whole and ego-centered networks. Whole network studies consist in asking interviewee about her relationships with closed (pre-defined) list of individuals; however, in an urban setting like the one studied this was unpractical. Then, an ego-centered approach was taken, which consists in asking each interviewee (ego) an open-list of individuals related with her (alters). The way the alter names are elicited heavily determines how many and who are the individuals in the individual’s network; in this case, instead of specific prompting questions, we preferred using a loosely definition of people “very close” and “somewhat close” to the interviewee. Both the ego-centered and the alter eliciting technique have conceptual consequences; the most important is conceiving the personal network as a Ptolemaic universe, with the ego in the centre and the alters around. That is, the data, although collecting interaction among individuals, is still individual-based. Another consequence of open lists is that the relationships between the alter and the ego, and among the alters is left to the interviewee’s criterion.

 

The paper then focuses in the way social activity-travel behaviour was linked after the social network was built. The interviewee was asked about frequencies of face-to-face and socialising meetings (the last one conceived as visiting, hosting or going to restaurants and pubs) with a sample of alters, and also the frequency of telephone and email interaction, some alter’s characteristics (including the main places they interact with the ego). In addition, we gathered explicit information about time and space characteristics of the last six social events with some of the alters. The main hypothesis behind this way of collecting social travel behaviour data is that the main individual’s social activities arise from the social network, that is, instead of directly start asking about their activities and travel, the main focus is on with whom the individual usually performs social activities. We believe in this way we are able to get a good sense of the individual’s socialising patters, although sacrificing some level of detail.

 

Finally, we discuss some limitations and the way they were minimised. A first limitation of ego-centered techniques is the risk of prompting a small network. We limited this drawback doing this exercise in the interview stage rather than in the survey, and using an analog instead of a computer approach. Regarding the decision of performing interviews, we believe this helped to gather more data than what we could have gathered in a survey format; controlling for the quality of the network building process; and finally getting a rich set of qualitative data, including comments, extra information, and the interviewee behavioural context. The analog approach we adopted consisted in using paper and pencil rather than a computer interface. This option diminished the burden in the interviewees and – we believe – also increased their motivation, especially because they built in step-by-step procedure their network in a paper, rather than adding names in a computer interface, which usually is a black box for the interviewees.

 

A second important limitation is the set of sampling procedures from the network. In fact, large networks were usually prompted and a sampling strategy was needed. We developed a sampling strategy based in a combination of the alter’s social closeness attributes and the frequency of interaction. This strategy balanced, on the one hand, capturing a relevant subset of the interviewee’s network (i.e. a relevant sample in their social space), and on the other hand, capturing a relevant set of her activity-travel events (i.e. a relevant sample in their activities and physical space). 

 

The paper also discusses the main qualitative and quantitative information obtained, and how both qualitative and quantitative approaches are complementary and useful to build and inform the conceptual model that motivated this data collection effort. Finally some potential future extensions and methods related with this data collection are discussed.

 

 

Visualizing personal networks: Working with participant-aided sociograms

 

B. Hogan, J.A. Carrasco, and B. Wellman

 

Abstract

 

We describe an interview-based data collection procedure for social network analysis designed to (a) aid gathering information about the people known by a respondent and reduce problems with (b) data integrity, and (c) respondent burden. This procedure, a participant-aided network diagram (sociogram), is an extension of traditional name generators. While 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.

 

 

Una revisión y análisis del modelo Logit Jerárquico

 

J.A. Carrasco, J de D. Ortúzar, and M. Munizaga

 

Abstract

 

Sorprende que, tras 25 años de haber sido formulado, aún no se comprendan cabalmente algunas propiedades del modelo logit jerárquico y se discuta su especificación. De hecho, este popular modelo ha sido objeto de una serie de acaloradas discusiones recientemente en la literatura. El objetivo de este trabajo es revisar las principales características del modelo en profundidad y examinarlas críticamente, a fin de aclarar todas las controversias. En primer lugar, se presentan los fundamentos teóricos del modelo, de forma concisa y fácil de entender, para luego examinar cuatro controversias en torno a su especificación: la correcta resolución del problema de no identificabilidad (común a todos los modelos de elección discreta), la aplicabilidad de la popular forma funcional NNNL, utilizada en el paquete estadístico ALOGIT, las reproducción de las particiones de mercado observadas y la pertinencia de una nueva especificación alternativa que provoca confusiones en relación a ciertas propiedades del modelo. Aparte del análisis teórico, se utiliza también simulación de Montecarlo para dilucidar algunos de estos aspectos. En este contexto, la principal conclusión del trabajo es que todas las hipótesis del modelo son esenciales para su correcta especificación e interpretación, y no deben ser ignoradas para un adecuado uso del modelo en la práctica

 

 

 

The Influence of Trip Length on Marginal Time and Money Values

 

Andrew Daly and J. A. Carrasco

 

Abstract

 

The work described in this paper is motivated by the strong empirical finding that the marginal trade-off between time and money in travellers’ decision-making appears to vary with the length of the trip. Specifically, travellers over longer distances appear to have a higher ‘value of time’ (VOT) and this effect appears to be caused by a declining marginal disutility of expenditure, rather than an increasing marginal disutility of spending time. There is no a priori reason to expect that VOT should increase in this way, indeed there seems to be good theoretical reason to expect an opposite trend, so that interest in this issue is natural. In particular, the consequences for project appraisal can be significant: is it correct to attribute a higher value to time savings for travellers making longer journeys than those making shorter journeys?

 
In practice, analysts have dealt with the effect in different ways for forecasting and appraisal, although the approaches that have been adopted can be justified only on the basis that they are approximations to an unknown ‘true’ underlying model. For example, the use of a ‘log cost’ formulation can improve the fit of models to data but is not reasonable with respect to individuals’ money budgets – the marginal disutility of expenditure must increase as the amount of expenditure increases.

To deal properly with these questions requires that an explanation is given for the observed effect. A number of hypotheses have been suggested to explain the effect and these are reviewed in the paper and their consequences assessed. Several of these hypotheses suggest that the primary mechanism by which VOT increases is through heterogeneity between individuals in taste relative to expenditure. Thus if individuals differ in their sensitivity to price, there will be a self-selection so that those making more expensive journeys will tend to be those with lower sensitivity to price. The effect can be reduced by segmenting the population, for example with respect to income, but an important degree of heterogeneity can remain.

The analysis is set in the Random Utility modelling framework because of the requirement for consistency with economic theory for project appraisal, because this was the basis used for the initial modelling with the data sets concerned and because this framework gives a good basis for modelling.


The work then set out to test the hypothesis of heterogeneity with respect to cost on data sets collected in different ways in different countries: Revealed Preference data from Sydney (1991/2 and 1997/8) and from Paris (1991/2) and Stated Preference data from The Netherlands (1988 and 1997). Existing models which incorporated distance-dependent cost sensitivity terms were reformulated and extended to incorporate heterogeneity of the type described, using a ‘mixed logit’ formulation to handle the heterogeneity. A number of problems had to be solved to reduce the volume of calculation. The analysis was restricted to commuters to keep its scope reasonable.


The results show variation between the data sets but that significant heterogeneity exists in all the data sets analysed. This heterogeneity exists for both time and cost, but more importantly for cost than for time. It appears that, on the whole, the assumption of heterogeneity with a linear cost disutility gives a better explanation of the effects observed – in terms of the fit of the model to the data – than the alternative hypothesis that marginal sensitivity to cost declines with increasing cost. An important further finding is that average VOT and elasticity with respect to time and cost variables can change significantly between different model formulations, and generally are more reasonable when the cost formulation is linear, so that it is quite important to find the right specifications for these models and advantageous to use the formulations with heterogeneity.


The results thus support the hypothesis of self-selection, but also hypotheses that higher prices are not well perceived or are valued proportionately could also be advanced on the basis of the empirical findings. The consequences for of the findings for appraisal would depend on which of these hypotheses were found most plausible. For forecasting, the consequences will remain limited, because it is not yet possible to use mixed logit formulations in large-scale forecasting.
 

 

 

A Joint Model of Vehicle Transactions, Activity Scheduling and Mode Choice

 

M. Roorda, J. A. Carrasco, and E. J. Miller

 

Abstract

 

A joint model of vehicle transactions, activity scheduling and mode choice is estimated based on a retrospective survey of vehicle transactions in the Greater Toronto Area. The vehicle transaction model includes, as explanatory variables, measures of activity/travel stress that are simulated using the Travel Activity Scheduler for Household Agents (TASHA). TASHA is a sophisticated activity-based microsimulation model of activity scheduling and mode choice that represents household interactions of vehicle allocation, ridesharing to joint activities, and drop-off/pick-up of household members. The empirical analysis and model results indicate that there exists an asymmetry in vehicle transactions. Households increase their activity/travel stress far more by disposing of a vehicle, than they alleviate stress by purchasing of a vehicle. Two measures of stress are found to be moderately significant influences on vehicle transactions: the mode choice utility gained by purchasing a vehicle, and the number of conflicts experienced in the household over a limited number of vehicles. This model makes a behavioural contribution by addressing the lack of sophistication typically found in the vehicle usage component of vehicle ownership / transaction models. The model also breaks new ground in the linking of long and short run decisions within a clear conceptual and modelling framework.

 

 

 

Spatial and Social Networks: The Case of Travel for Social Activities
 

 J. A. Carrasco, E. J. Miller, and Barry Wellman

 

Abstract

 

Hägerstrand’s argument that Regional Science is about people and not only locations is still a compelling and challenging idea when studying the spatial distribution of activities. In the context of social activity-travel behaviour, this issue is particularly important since the main individuals’ driver to perform a trip is mostly with whom they interact rather than where they go. Using a personal networks approach to measure and study social activity-spaces, which focuses in the relationships of specific individuals (egos) with others (alters), this paper conceptualises social and physical space as a phenomenon beyond the traditional individualistic perspective, showing the need of studying interactions between individuals in a more explicit way. The paper presents the relationships between social activity spaces and the characteristics of egos and their personal networks. Overall, the results strongly suggests that, although –by definition – the spatial distribution of social interaction is an idiosyncratic phenomenon, there are several systematic effects, related with the characteristics of egos and their personal networks, which affect this spatial distribution, and which can serve to better understand where people perform social interactions with others.