Current available papers outlining projections of UK government expenditure on infrastructure in the medium term suggest that the trend is on the up. The obvious inclusions in this are the substantial spend on extension of the high-speed railway network, as well as substantial expenditure in the road network throughout Britain. This suggests some very exciting times ahead for our profession with many new challenges. In addition, we have recently seen the successful opening of two very large cable-stayed road bridges in the UK, testament to our profession and the UK teams that delivered design.We all, as professionals, now see the challenges of the continuing focus on ways to improve quality of design, reduce cost of design, design in collaborative environments and the desire to speed up the design process. We are privileged in the UK to have this journal, which offers us the opportunity to exchange our experiences in design and enable those with developing methods to publish them for consideration by peers, which can only help us respond to the challenges made to our profession. This edition of Bridge Engineering includes a number of papers that do exactly that, with many focussing on the assessment and reliability of existing structures.In their paper, Hendy et al. (2018) present the findings of a study examining the impact of reducing partial factors in the UK assessment standards. Their study was undertaken for Highways England and was implemented on the back of adoption of a similar method in the Netherlands. They argue that adoption of such a method could be applied, ensuring appropriate structural reliability levels are maintained for existing infrastructure while the cost of strengthening existing infrastructure is reduced in comparison with the status quo.Hanley et al. (2018) present their study, which determines the reliability of three bridges by applying live load prescribed in old UK loading standards and in contemporary standards. They demonstrate that the older bridge stock is less reliable when assessed to more modern standards. They also quantify the increase in reliability that can be gained when assessing using real traffic loads. Proske et al. (2018) present their research into the transverse forces generated on masonry arch bridges by debris flow. Their study also encompasses the behaviour of this type of bridge under this dynamic force. Their study highlights the shortfall of research into transverse debris loading on bridges in comparison to the vertical loading generated by this event.An interesting comparison of predicted scour depths using US Federal Highway Administration scour analysis methods with laboratory studies is made by Latifi et al. (2018). Their paper applies these methods to the very substantial 300 m long, 33 span double-deck stone arch Sio-Se-Pol Bridge in Iran. In this comparison, the authors found a good comparison between the methods that they employed.Imam and Salter (2018) present their study into the accumulation of fatigue damage in riveted plate girder railway brid...