Collecting travel diaries: Current state of the art, best practices, and future research directions

The amount of useful information that can be extracted from travel diaries is matched by the difficulty of obtaining travel diaries in a modern era where the response rate to traditional travel diary collection methods has seen a decrease in most countries. Prompted by this, a body of research has been dedicated to study how travel diaries can be collected via new methods, namely location enabled devices such as smartphones, that have a higher penetration rate (in terms of device ownerships and user attachment) and are both easier and cheaper to manage compared to traditional data collection method, e.g. paper-and-pencil, phone, or web-based questionnaires. This paper offers an overview of the current state of travel diary collection, a potential future state and a practical checklist for travel diary collection case studies. A thorough discussion on different pros and cons of travel diary collection methods and efforts needed for the convergence of methods to collect travel diaries for all demographics are provided. The practical checklist to aid researchers to organise case studies is based on the authors’ experience and it is meant to raise awareness of difficulties that can be encountered while collecting travel surveys with automated and semi-automated systems, and how to overcome them.