Person wearing a headset conducting a phone interview, representing the role of qualitative data collection through in-depth interviews in travel behavior research.

A close-up of a person with a headset engaged in a phone call while looking at a computer screen. This image symbolizes the use of structured, phone-based interviews to collect qualitative insights from participants—particularly those underrepresented in traditional surveys. These conversations provide critical information about foregone travel behavior and access challenges that may not be evident in diary-based or quantitative datasets.