Crammed together in tight folds of humanity, the suburban rail passengers of Mumbai, India, experience the most densely crowded trains in the world (Basu & Hunt, 2012). Whilst the immediate physical descriptors of crowdedness in Mumbai are well understood (Hirsch, 2016), there is little knowledge of the effect this has on the multitude of passengers. This is an important omission, as the effects of crowding on passengers impact their attitudes, travel behavior, and travel decisions. This paper therefore seeks to discern the physical, emotional, and behavioural effects of rail passenger crowding in Mumbai, India. To achieve this, a qualitative methodology, including 49 face-to-face interviews and 48 hours of ethnographic and autoethnographic observations in Mumbai were conducted. Mumbai is an ideal place to study these effects as it has high-density crowding, the likes of which are not experienced elsewhere. Additionally, there is a limited understanding of the effect of crowding on passengers in non-Western societies. With increasing rail ridership worldwide, the experiences of Mumbai's passengers within high densities may align with the future experiences of passengers in other Western and non-Western countries. For academics and service providers, understanding the specifics of the crowd, such as the density, passenger perceptions, and culture is important. With that knowledge, strategies to improve the experience of crowding would be more effective. Keywords: Rail Passengers, Crowding, Effects, Behaviour, Emotion, Transportation The Effects of Crowding on Humans Since the 1970s, a range of disciplines has studied human crowding. These studies encompass mundane crowding, such as being on a crowded train (Gomez-Jacinto & Hombrados-Mendieta, 2002) and extraordinary crowding, such as at festivals, or stadium stampedes (Davis Associates, 2003). Despite this variability, there is agreement on the definition of crowding. Crowding is a "group phenomenon" (Epstein, 1981, p. 370); for crowding to occur, a space must be shared with others. Reduced freedom of movement and an increased demand on physical coordination is an outcome of the shared space (Baum & Paulus, 1987; Saegert, 1973). This, coupled with people's feelings and experiences in that space result in crowdedness (Thompson, Hirsch, & Rainbird, 2011). Much psychological research adheres to a negative view of crowding, claiming it to have antisocial (Lee & Graefe, 2003; Punpuing & Ross, 2001; Le Bon, 1985, in Reicher, 2002; Ryan & Cessford, 2003) and other negative emotional and behavioural impacts on people (Langrehr, 1991). The aloof and unfriendly manner attributed to many dwellers in large, busy cities (Milgram, 1974) reflects this. The phenomenon of increasing interpersonal detachment in association with increasing numbers of people has been observed for decades. The particular tactics employed by individuals to create and maintain social distance (or reduce and avoid unwanted social connection) have been the subject of much research. For example, Goffman's Theory of Civil Inattention (1963) and Hall's Theory of Proxemics (1966) describe how people use tactics to actively avoid the attention of, and engagement with strangers in public. These can be seen in relation to train riding, when people avoid eye contact with passengers or change their posture to disengage from their surrounds (Evans & Wener, 2007; Hirsch & Thompson, 2011b): Erving Goffman's Theory of Civil Inattention (1963) described particular codes - subtle behavioural changes - that strangers in public follow to assign their own personal boundaries and remove the necessity of facing, or imposing on others. Through this behaviour, people in public spaces are able to maintain a comfortable social order. Goffman's observations were based in the US and UK during the 1950s and 1960s. He stated that considerations need to be taken into view in case of possible infractions to the theory, when looking at other countries, other cultures, and other times. …