The ITF has produced a series of reports and discussion papers addressing the interrelated issues of railway structure and performance; see for example Beck et al. (2013), Thompson (2013), ECMT (2007) and, Thompson (2007). The academic literature on this subject is also significant, with good examples in Mizutani et al (2014), Nash et al. (2013), Van de Velde et al. (2012) and Kirchner (2002, 2004, 2007 and 2011). All of these studies have confronted the question of how to measure the performance, or efficiency, of railways both in the sense of how one railway compares with others (cross-section) and how railways have changed as a result of policy interventions (time-series). The purpose of the roundtable discussions was to revisit the issue of how to define and measure efficiency at the proper level of detail and with reasonably available data so that policy makers can benchmark the performance of their railways, evaluate the impact of past changes in railway structure, ownership or regulation and assess the likely outcome of future initiatives. The challenge is inherent in the phrases “proper level of detail” and “reasonably available data”.