ABOUT THE IMPACT OF PERSONALITY ATTRIBUTES ON THE TRANSPORT DEMAND FORECASTING AND BENEFITS ESTIMATION. A CASE STUDY IN CONCEPCION
Arnoldo Tapia, Universidad De Concepción, Alejandro Tudela, Universidad De Concepción, Juan Antonio Carrasco, Universidad De Concepción
The goal of this article is to study the effect of psychological variables on demand forecasting when they are incorporated in a discrete choice model.
The incorporation impact of psychological variables on modal split and benefits quantification is studied in this work. Mode choice is modelled as a function of personality variables. The selection of these variables is rooted in the Theory of Interpersonal Behaviour proposed by Triandis. This theory states that the observed behaviour is due the interaction among the intention to develop a conduct, someone’s habit and the context under which the decision is being made. Intention is explained by three factors: someone’s attitude with respect to an object or situation, the emotions someone develops towards the object, and the social descriptors of the individual: role, norm and self-concept. All these variables can be described as latent in terms of modelling.
Information about attitude, affection, habit and contextual situation was gathered in the city of Concepción, Chile. This information was collected years 2007-2008 and 2011-2012. University workers were interviewed during the first period whereas people from the Collao neighbourhood were interviewed in the second one. A total of 535 records were available for modelling purposes.
Different demand models were estimated, incorporating the personality variables through a latent variables approach, using structural equation modelling. Sequential and simultaneous estimation methods were used. Preliminary results show that attitudinal factors and habit help to improve the models goodness of fit when compared with a model without the personality attributes (named classical model). Besides, changes on the cost and travel time elasticity and modal split are observed when these factors are included in the models.
Classical and improved models were used to quantify changes on users’ benefits due to a transport intervention in Concepcion. The Cost Benefit Analysis approach being used in Chile was used to run these calculations. An interesting result is that benefits when considering the attitude and habit factors are smaller when compared with the benefits obtained when these factors are not taken into account in the demand models. These result might change outcome of the decision making process since net benefits might not satisfy the minimum standards defined in the social assessment methodology. Transport investments process would be challenged.
Association for European Transport