This publication contains guidance on a variety of topics related to the assessment of concrete bridges. Following the publication of BD21 in 1984, bridge assessment has become an increasingly-important function in the UK as the post-war generation of concrete bridges ages and has more demands placed upon it. Nevertheless, it is recognised that sub-standard bridges still exist and are in need of proper and professional assessment in order to maintain a healthy and safe national bridge stock. The purpose of this publication is to both record the experiences of the past and to offer examples of best practice for the future. It covers a wide range of topics and is well-illustrated.