Abstract
Social networks have one of the central roles in the life of every individual. They influence our mental and physical health, length and quality of our lives, and provide us with support, information and opportunities in life. Our opinions, life choices, even our mobility are determined by the structure and type of our social connections. Therefore it is not surprising that many fields of science were interested in studying the structure and dynamics of social networks. As a result, we have different definitions and methods for the quantitative analysis of social networks which depend on the studied problem and/or phenomena. This chapter provides an introductory summary to the definition, theory and application of social networks theory in the field of transportation studies, economy and physics. We review major concepts and results from different fields of science related to social networks study and show which of these concepts can be useful in studying how social networks influence travel behaviour.
