Ben Gilmartin
Principal Risk and Safety Intelligence Analyst, RSSB
Two criteria drive the decisions railway stakeholders make when they’re proposing new measures. One is cost, the other is improving safety. Under the Health and Safety at Work Act, it’s a stakeholder’s legal responsibility to ensure safety ‘so far as is reasonably practicable’.
That isn’t necessarily as easy as it sounds though. If you're looking to make business improvements by reducing costs, you really have to understand the safety implications associated with those improvements; it's extremely hard to justify making safety worse in order to make a cost saving.
The Taking Safe Decisions framework
The Taking Safe Decisions (TSD) framework was developed in the early 2000s to provide guidance on aspects of good practice grounded in risk-based evidence. It helps people make decisions that keep staff, passengers, and others safe, while satisfying both the law and stakeholder interests, and remaining commercially sound.
TSD is applicable to all decisions you might have to make, whether they're safety decisions or business decisions generally. The recent TSD e-learning package is designed to be accessible to a wide audience—not just the safety community, but also board members, directors, project managers, engineers, and suppliers, because it's applicable to so many decisions that support industry’s ability to ensure safety.
It's supported by the Office of Rail and Road, so if they should express an interest in how you're doing things at any point, following the Taking Safe Decisions principles—in whatever form that applies to you—will serve you well.
Taking the strain out of quantifying risk
Sometimes you might need to quantify risk to support your decision-making. To do so, you'll need to carry out a cost benefit analysis. Look no further than RSSB’s Cost Benefit Analysis (CBA) guidance for help with that, which was refreshed and published in 2025.
The guidance shows you how to balance costs and safety benefits, and to ensure you're able to justify your decision-making. In addition to that, the specific CBA tool is available to help our members do all this in a way that's consistent and as easy as possible. And of course, quantified risk data can be extracted from the RSSB Safety Risk Model.
Taking Safe Decisions in action
A good example of TSD and CBA in effect is PRIMA, an operational planning tool that’s used to manage the risk from running in poor weather by informing decision-making about speed restrictions.
Another is our project T1324, which was used to develop a method for assessing and managing the safety-related impacts of medical impairment in train drivers. TSD provided the framework for that work, which took place in 2025. It represents a step towards bringing health into parity with safety, and taking the same risk-based, evidence-based approach to it.
Empowering your decision-making
In short, TSD provides a structured, evidence‑based approach that helps rail organisations make consistent, transparent, and proportionate safety decisions by balancing risk, cost, benefits, and legal duties within a set of clear guiding principles. Using it should put you in an informed position to be able to justify and defend your organisation’s decisions, particularly in times of change.