Communication errors feature prevalently as causal and contributory factors in accident analysis within rail. While matters of phraseology and protocol in communication have been used to categorise communication error, formal inquiries into major rail accidents point to an underlying "authority gradient" as an influencing factor. The aim of this paper was to understand how the influence of authority gradients on communication error has been explored by communities of research and practice in rail. To achieve a holistic understanding and identification of key research gaps, this paper also reviewed prevalent tools and frameworks applied in rail human factors, as well as other sectors impacted by power disparities between teams. The review found that while evidence from industry reports is suggestive of an authority gradient in rail, no research has been conducted to support or refute this conclusion. Moreover, an absence of authority gradients in applied research draws attention to current methodological capabilities vs research foci. The relationship between the authority/power and status/ value of core rail operational functions is conceptualised, and application of Hofstede's theory of power distance to rail is considered. A number of research gaps are identified which indicate future research opportunities. Relevance statement Industry reports and Inquiries into major rail accidents draw attention to an underlying "authority gradient" as an influencing factor in communication error, resulting in near misses and fatalities. A number of human factors tools, methodologies and frameworks have been applied in the context of communication error in rail, but there is little to indicate that the influence of authority gradients has been uncovered or has been the focus of research activity to date. Consequently, power disparities between team workers are being addressed using individual-level training approaches, which means the nature of communication error is not being accurately represented. The prevailing theory for authority gradients, Hofstede's power distance dimension of cultural relativity theory, has not been applied to rail previously and is considered in relation to research gaps for understanding