The time is 0534hrs on the morning of Friday 15 April 2022. The scene is West Town Road in Avonmouth, Bristol, beneath the northern end of the M5 Avonmouth Bridge. The first train of the day on the Severn Beach Line is GWR Class 165 DMU no. 165129, forming 2K00, the Bristol Temple Meads (0510hrs) to Severn Beach service. Here it speeds over the level crossing at the entrance to the Avonbank Industrial Estate.