Rail and transit construction projects are complex undertakings and, as in many industries, railway technologies have become increasingly complex over time, resulting in the need for an independent safety assessment that ensures the system will behave in the manner that it is intended when constructed.

Independent Safety Assessment (ISA) is the formation of an independent judgement, separate and independent from all railway engineering design, development, or operational personnel, attesting that the safety requirements for the railway project are appropriate and adequate and that all the systems and civil works assets as well as Operation and Maintenance (O&M) processes are compliant with those safety requirements. This results in a system that satisfies the safety requirements as provided in the European Standards of CENELEC 50126 (Railway Application of Reliability, Availability, Maintainability and Safety), 50129 (Standard in Railway Systems for Railway Signaling), and the “Yellow Book.”  To that end, the objectives of the ISA are to:

• Independently verify that risks have been identified and reduced to an acceptable level.
• Provide acceptable confidence level to stakeholders on safety matters.
• Ensure safety requirements are met throughout the project life cycle.

The Independent Safety Assessor’s role is to perform specific assessments and/or audits to establish the maturity and rigor of the safety management process without getting involved directly in the design and construction.  The ISA assesses how well safety is implemented into the project. They ensure that:

• Independent judgements and opinions are free from project constraints
• The project has a completely independent risk-based assessment that encourages creativity and active engagement focused on safety, process, compliance, operations, and organizational competency.
• Reduction of project risk due to competent third-party input.
• Safety arguments as well as the treatment of railway hazards and risk have been appropriately and effectively addressed and mitigated.
• The project is delivered in compliance with railway standards regarding safety targets.
• Operators are given increased confidence, independent from potential supplier constraints.
• Technical and commercial stakeholders as well as regulatory bodies are assured that the project is managed professionally, and safety targets are met.

ISA is required by law in many countries and many large rail and transit projects currently utilize ISA, although this approach has not yet penetrated the U.S.  market.

The process to apply ISA process follows several over-arching steps, starting with the proposal stage, as follows:

• Clearly define the ISA scope and purpose and ensuring that ISA staff understand the project.
• Assemble an ISA team with the right backgrounds and expertise, inclusive knowledge in all rail transit system elements and O&M.
• Gather and review project documentation.
• Review existing safety cases/certification, hazard analyses, and risk assessments.
• Conduct system walkthroughs and interviews.
• Review and evaluate organizational processes.
• Report detailed findings, observations with recommendations for clear and implementable actions. Note that ISA must not suggest how the project should carry out its development.  The project must own all design decisions.

Once enacted, ISA delivers several benefits. It considers the overall safety of a system, including processes, organizational capabilities, documentation, and safety culture, thus providing a holistic view of safety for the project.  Specific benefits are:

1. Enhanced Safety Assurance
2. Compliance with Standards and Regulations
3. Risk Reduction and Mitigation
4. Improved Decision-Making
5. Increased Stakeholder Confidence as ISA provides a holistic View of Safety. Unlike specific risk assessments (e.g., hazard analysis), ISA considers the entire system life cycle including the evaluation of both technical aspects and organizational processes and safety culture.
6. Support for Certification and Accreditation
7. Early Detection of Safety Issues
8. Efficient Resource Allocation
9. Culture of continuous improvement

In summary, ISA contributes to safer, more reliable systems, instills confidence, and supports informed decision-making.

Nevertheless, implementing the steps to achieve the benefits comes with challenges. For example:

• Inconsistency in Identifying Significant Risks: Different practitioners may interpret risk factors differently, leading to different outcomes.
• Understanding System Internal Controls: Obtaining a comprehensive understanding of an organization’s internal control system can be a complex task requiring careful analysis.
• IT Risks: With increasing reliance on technology, ISA professionals must explicitly consider IT risks.
• Application challenges for Small and Medium Sized Agencies who have limited resources.
• Keeping Up with Evolving Standards.

Owners considering ISA for their projects should be aware of these risks and make certain their independent ISA providers have adequate measures in place to address them.

The risks inherent in large rail and transit projects are compounded by the complexity of these projects, with numerous stakeholders, systems, requirements, and other factors combining to create circumstances ripe for accidents. ISA offers owners and teams a way to better manage and mitigate these risks through an unbiased independent assessment, leading to safer projects and, ultimately, safer and more reliable systems for the long term.

ONALA ATALA, PTSSP, PTSCTP: Hill International Senior Rail and Transit Sector Subject Matter Expert (SME) Onala Atala is a strategic expert in transit & rail systems. His skills include managing large scale rail transit projects, systems engineering and management, safety & security certification, fire/life safety, state safety oversight, proposal writing, and computer simulations. Onala served as Project Manager of the Lusail LRT in Doha, Qatar, and on the Taiwan High Speed Rail Corporation serving as the Director for Systems Assurance, leading a team of over 40 multi-national professionals, successfully delivering the safety certification of the Taiwan High Speed Rail system, among other assignments.

NAVINCHANDRA S. SAGAR, PE: Hill International Senior Rail and Transit Sector SME Navinchandra “Navin” S. Sagar has nearly four decades of experience of public/ private experience in multi-modal rail and transit programs. His expertise encompasses rail/transit infrastructure programs, systems, rolling stock, planning, engineering, construction, construction management, QA/ QC, systems assurance, cyber security matters, closeout, operation, and maintenance with constant performance monitoring.