Improving the quantification of safety risk arising from delays and disruptions
Rail often relies on operational restrictions to mitigate risks from adverse weather or asset conditions. For example, speed restrictions or early terminations of journeys.
This can lead to crowding on stations and platforms, which makes accidents more likely. Train drivers could also experience more red signals, increasing the likelihood of a signal passed at danger (SPAD).
Research was needed to update and improve our understanding of the link between performance and safety. And, to provide a recent, data-led, factual evidence base to quantify safety risk from delays.
This research project built on the original knock-on risk model to bring it up to date with more granular, post-COVID data.
We found that on days with lower performance, there was a higher likelihood of safety incidents such as SPADs, slips, trips, and falls, platform train interface incidents, and staff assaults. This demonstrated that, while delays are not safety events in and of themselves, they can lead to knock-on safety risks.
We also considered the long-term effects of delays and disruption in the form of modal shift to other modes. Lastly, this work has modelled and quantified knock-on risk in the context of stranded trains.
The availability of robust quantification of the safety risk from delays and disruptions helps make balanced decisions that consider the different ways safety is impacted.
This research showed that delays can lead to safety risks. This was quantified as 32 FWI per year related to delays.
These outputs will inform:
- Plans to respond to adverse events.
- Policy and investment decision.
This will help to improve the performance and safety of the railway.