I’m multimodal, aren’t you? How ego-centric anchoring biases experts’ perceptions of travel patterns

Abstract

Transport professional process an enormous range of information to help them accurately predict how, when and where people will use the transport system. Yet we know from a long-standing history of psychology research that people draw upon a range of mental shortcuts when making estimates about the world. Ego-centric anchoring and adjustment is a common example of a mental heuristic whereby people draw upon their own beliefs and experiences when estimating the behaviors and attitudes of others. Do transport professionals use ego-centric anchoring when estimating travel patterns? To find out we conducted a survey of transportation professionals (n=247) who were asked to reveal their own travel patterns and residential location and to estimate the travel patterns of millennials, generation X, and baby boomers.We find that relative to the average American, transportation professionals in the US are more likely to use alternative transport modes and live in more urban neighborhoods. Transportation professionals systematically over-estimate the use of alternative modes (and under-estimate driving) among other Americans. This effect is strongest among transportation professionals who themselves are multi-modal.These results raise a note of caution for transport practitioners and policy-makers to be aware of one’s initial ‘anchor’ of personal experience when judging the behavior and desires of the community. For example if practitioners overestimate the proportion of Americans that are already walking, biking, and using transit, they may under-estimate the policy and institutional barriers that have led the majority of Americans to follow the car-dominated path of previous generations.