Nudging "The Man on the Clapham Omnibus": Designing Behavior in Captive Environments

This paper explores the relationship between passenger behaviour and the nudges created through cabin design in public transport vehicles such as trains, trams, buses and aircraft. Behaviour onboard such vehicles is a sophisticated landscape, with unspoken rules of appropriate behaviour according to the broader culture, or indeed the culture of vehicle type or even time of day. For example, on an aircraft, passengers are actively and passively discouraged from accessing the bathroom during meal service. On trains, standing passengers are expected to place their bags on the floor or in front of them during rush hour. On buses, passengers seated at the aisle are expected to be vigilant towards the body language of those seated at the window, should they wish to alight.

Such “expected” behaviour of public transport passengers has become a benchmark for what might be considered reasonable. In 1903 a person of "legal fiction" called "The man on the Clapham omnibus" was first used in English Law as the standard for an ordinary and reasonable person. To this day, in many legal systems across the world, whenever a court came across scenarios such as a civil action of negligence, where it is necessary to decide whether a party has acted reasonably, a similar figure is still used as a standard of behaviour. In Melbourne (Australia) this person is "the man on the Bourke Street tram", in Hong Kong (China), the equivalent is "the man on the Shaukiwan Tram".

Interestingly, and perhaps worryingly, is that many behaviours considered to be acceptable or deplorable for "The man on the Clapham omnibus" are results of nudges and limitations posed through the design of such an omnibus. For example, evidence shows strong correlations between the number and location of access doors and passenger boarding behaviour in trains, while the type and application of lighting strongly influence passenger sleep behaviour on long-haul flights. Is “The man on the Clapham omnibus” of intrinsic reasonable character, or is his behaviour shaped by social norms, or nudges within the design of the Clapham omnibus?

Based on the observation that between ports, passengers are captive in such vehicles, the paper proposes that design nudges in this field are subject to some unique circumstances. Coupled with the notion that public transport is a complex product-service-system, the authors draw correlations between cabin design and passenger behaviour. The paper will then present an argument for how some of these behaviours resulted from design nudges and how they have possibly continued to influence the landscape of acceptable public behaviour in a feedback loop.