‘Informal Travel’: A New Conceptualization of Travel Patterns?

Abstract

In transportation, informal transport refers mainly to the use of paratransit services in the developing world. In this paper we argue that informal travel may include, in addition to mode and users, also other travel pattern elements, such as trip planning, structure, purpose, and destination. Each of these can be placed along an axis ranging from formal manifestations to informal ones, thus creating a ‘formality scale’. Moreover, these elements may be combined in numerous ways, creating a multitude of travel patterns that may be placed all along the formality scale. After providing a definition of formal, semi-formal, and informal travel and characterizing travel patterns according to the formality scale we identify population groups which exemplify semi-formal and informal travel patterns. Next, we analyze the 2009 US National Household Travel Survey, which suggests informal travel may be growing. This leads to a discussion on various factors that might affect travel formality. Most notably, the growing use of information and communication technologies may be shifting travel toward the informal end of the axis. In turn, this might affect trip symmetry, which may result in further effects on the transportation system.

Keywords:

• ICTs
• travel patterns
• informal travel
• travel formality
• travel elements

Acknowledgments

The authors would like to thank Professor Deborah Shmueli and Professor Michael Wegener for their insightful comments and remarks. We would also like to thank the three anonymous reviewers for their comments and suggestions.

Notes

1 We distinguish between the planning process, which includes decision-making regarding various travel pattern elements, and the decisions made regarding these elements. This is due to the fact that each element, on its own, uniquely affects overall travel patterns. Thus, in this paper the planning process refers to whether planning was implemented or not and not to the outcomes of this process (e.g. choices regarding mode, route, destination, etc.). For instance, commuting by private vehicle may be undertaken after careful planning regarding mode or route. On the other hand, the same mode or route may be undertaken out of habit.

2 Origin is not referred to in this discussion since it generally does not include a dimension of choice. Having said that, in certain situations origin may still have an effect on trip formality, as some origins may constrain the individual to specific travel elements while others may provide more alternatives (for further reference to residential location-based constraints, see Section 4.1.2).

3 The suggested formality scale may be linked to the utility–disutility (from travel) scale (Mokhtarian & Salomon, 2001). However, we do not see these scales as overlapping as each form of travel formality may provide unique utilities: formal travel may provide utility by allowing multitasking, while the utility derived from semi-formal trips stems from their potential flexibility and the utility of informal travel is derived from the trip itself.

4 These costs are commonly referred to as generalized costs.

5 Another relevant group is tourists. However, the informal travel of tourists is out of the scope of this paper.