Human Factors Design Considerations For Safe Train Operations

Introduction:

People, procedures, working practices, infrastructure, regulations, and interdependent systems with multiple interfaces make up the Rail Rolling Stock, a modern and complex socio-technical system. The efficiency, safety, and sustenance of Rolling Stock systems are essential to advancing the economy and society. Achieving higher reliability and ensuring commuter safety has been a crucial requirement for efficient rail operations as the performance standards for rolling stock design have become more stringent over time.

One of the key aspects of improving the rolling stock systems’ safety is through high-quality engineering designs that integrate human factor principles to create and establish a conducive environment to confirm all appropriate safety measures are in place for reliable and safe travel. It is, therefore, crucial that human interactions with the system are effectively designed with proven human factor concepts with expertise for rolling stock to provide the desired levels of benefits to passengers for a safe and comfortable journey.

In this white paper, we will discuss the growing need for human factors and usability engineering designs for rail systems that could be achieved through understanding and integrating the key human factor elements to optimize the safety and overall performance of the rail system and human well- being. We will also discuss the necessity of considering the need for human factors early in the projects to establish the scope and emphasis of activities that will bring value to the project goals by considering passengers’ demands, behaviors, and interactions and how human factor-centric designs should play a critical part in optimal system usability with increased user satisfaction and promoting passenger safety.

Key Elements of Human Factors Design:

Human factors include a wide spectrum of physical, mental, and emotional aptitudes and limitations that can change depending on the person, situation, and time. Thus, systems or products must be designed using psychological and physiological principles that improve performance and safety.

While designing interactive systems that engage people, tools, and technology, human factors engineering must consider human capabilities and limits to ensure optimal system availability, decrease the possibility of human mistake, improve safety, and increase usable system performance. To better accommodate people’s abilities, limitations, and demands, it is essential to create system designs that serve human purposes and help users adequately control the environment within which they traverse.

A multidisciplinary approach is therefore necessary for integrating human factors into systems or product development life cycle. It requires a combination of knowledge and abilities from several disciplines like engineering, management, ergonomics, psychology, etc. Some of the key human factor elements that engineers need to account for in the design and evaluation of systems are as follows:

a) Understand the user: The first step in human factors design is understanding the user. This includes understanding their needs, capabilities, and limitations.

b) Consider the context of use: The next step is to consider the context of use. This includes the environment in which the product or system will be used, the tasks that the user will be performing, and the goals that the user is trying to achieve.

c) Design for usability: The goal of human factors design is to create products and systems that are easy to use and understand. This includes ensuring that the controls and displays are easy to see and understand and that the tasks can be performed efficiently and effectively.

d) Test and evaluate the design: Once the design has been created, it is important to test and evaluate it with users. This will help to identify any problems with the design and make necessary changes.

e) Be iterative: Human factors design is an iterative process. This means that the design should be continuously improved based on user feedback.

Implementing high-quality engineering designs with integrated input from human factors and operations management becomes crucial in achieving the desired objectives. Understanding human performance and user requirements and involving users’ needs in the design process helps create solutions that align with their capabilities and preferences and reduce the risks and costs associated with integration failures.

Rail Human Factors Engineering:

According to Hammerl et al. [1], Rail Human Factors are defined as “the scientific discipline concerned with the understanding of interactions between humans and the railway system, with the purpose of optimizing safety and overall performance of the rail system and human well-being”.

Quality of service, dependable and safe performance, and optimal capacity utilization are a few important objectives for successful rail operations. The Rail Human Factors Engineering activities should focus on creating tasks, processes, and work environments that are in harmony with human capabilities and limits. In recent years, it has been noticed that the level of awareness of the importance of human factors in railway equipment designs is increasing, and such consciousness is crucial to improving system reliability and human performance as well as safety [2].

Ergonomic and accessibility factors have a greater impact on the design of a variety of rolling stock components, including seats, lighting, temperature, noise, ventilation, signs, and controls. Safety for both individuals and the system, human competence, and human constraints are a few things that must be considered in the early stages of system design. It is important that the human factor requirements are established, and the human factor program of activities is coordinated with that of the other disciplines throughout the various design phases. Mannequins can be used in computer-aided design (CAD) evaluations to guarantee anthropometric fit for the target audience and compliance with sight line criteria. With an emphasis on the interaction between a human and the object of interest, rolling stock design solutions should focus on optimizing the products or environments to reduce human errors, increase situational awareness, and improve human-system interactions.

Human Factors Integration (HFI) in Rolling Stock Designs:

Design principles of human factors comprise improving physical interaction between the rolling stock and its users (passengers), to meet the user’s bio-mechanical constraints. The EN 50126-1 standard for railway technical component system design mandates the inclusion of human factors in designs and places a strong emphasis on the integration of human factors into the systems. It has, therefore, become a necessity to recognize human factor design as a critical discipline to be integrated into the initial stages of the rolling stock designs, as it often becomes impractical and excessively costly to make changes after the creation of new systems. To be fit for purpose, rail systems and goods must have their intended use and the technical issues they are meant to address clearly defined throughout the various design phases. Ignoring the human components of design can result in a severe reduction in system performance and the loss of personnel due to accidents, which can cause significant financial implications.

Any inaccurate, inconsistent, or biased input could result in a poorly designed system and will have low user acceptance. According to ISO 9241-11, the human usability factor is the ability of a new product to be used by specified users to fulfill stated goals with competency, effectiveness, and happiness in a given usage environment (railway) [3]. It is, therefore, important that rolling stock designers and engineers understand the requirements, interests, and expectations of passengers and operators. This will help them design comfortable seating arrangements, lighting, displays, and communication channels that provide clear and unambiguous information to make users understand what is appropriate and potentially safe and control installations that are well set up and easy to reach.

A few of the factors that designers need to consider while train systems are conceptualized are:
⦁ the physical capabilities and limitations of passengers, such as their age, size, and strength
⦁ the cognitive abilities of passengers, such as their ability to understand instructions and make decisions
⦁ the emotional state of passengers, such as their stress levels and anxiety, and
⦁ the environmental conditions in which the rolling stock will be operated, such as the level of noise and vibration, etc.

Key HF Aspects Influencing Passenger Safety in Rolling Stock Designs:

Below are some key aspects that should guide the design of rolling stock products/systems and their interfaces to create user-friendly, efficient, and safe solutions that meet the needs of the passengers. By integrating human factors design principles into rail rolling stock operations, the aim should be to create a safe and comfortable environment for passengers, facilitate effective communication, and ensure that appropriate safety measures are in place to protect passengers throughout their journey.
⦁ Accessibility: Designs for rail systems should consider the demands of passengers with impairments or limited mobility. This might entail providing wheelchair-accessible facilities like ramps, lifts, universal access toilets, and dedicated places. Clear signs, tactile markers, and auditory announcements for visually challenged travelers should all be considered during the design. Making sure everything is accessible improves passenger’s safety and inclusivity.

⦁ Emergency Evacuation: The design of the car body, doors, and associated equipment must consider emergencies, and passengers should have a provision for a quick and safe escape during an evacuation. Emergency exits must be prominently displayed, simple to find, and built to accommodate a steady stream of passengers. Passengers should be informed of and effectively conveyed emergency procedures and directions.

⦁ Clear Information and Communication: Designs should ensure that all passengers can access and use communication systems that are dependable and simple to understand. Clear information and efficient communication mechanisms for passengers should be included in audio/video equipment designs to guide passengers about approaching stations, interconnections, and safety precautions, as required. These instructions may include thoughtfully designed passenger information displays, voice announcements, and visual signals.

⦁ Control and Display Design: The goal of control and display designs should be to provide intuitive, understandable, and ergonomic panels and exhibits. Controls should be logically arranged and labeled so that passengers can operate them with ease and accuracy. Displays should transmit relevant information that is easy to understand, reducing cognitive burden and promoting quick decision-making. Controls that successfully combine aesthetic appeal and usefulness leave a pleasant impression and make passenger operations simpler.

⦁ Interior Design: Passengers’ interior environments should be made safe and comfortable through interior designs. This may include well-placed chairs, railings, grab bars, clearly visible signages, and adjustable seats, giving commuters the ideal working and traveling conditions. One of the human factor considerations for designing cab interiors is incorporating a safe, cozy, easy-to-maintain place free of unnecessary distractions. The design should be flexible enough to meet the requirements of all passengers, including those with special needs or limited mobility.

⦁ Safety Features: To protect passengers from any causalities, designs for rolling stock should include all safety elements and follow relevant regional and international standards. The design features could involve actions like automated opening of doors, efficient fire suppression systems, and reliable and fail-proof emergency brake systems. Also, since the railway systems are quickly transitioning to partially automated, driverless, and unattended train operations, designing fail-proof and safety-critical systems is increasingly important. Both passengers and staff (rail operators) should be able to use the safety features easily and with high reliability.

⦁ Crowd Management: The design of pathways, door openings, etc., should consider managing passenger flow and crowd behavior. To reduce congestion and ensure smooth passenger movement, design elements should leave enough room for passenger mobility, strategically place handholds, and have clear routes earmarked. To lower the risk of accidents, adequate signage and instructions must be provided to support passengers during boarding, alighting, and transfers.

⦁ Effective Maintenance and Inspection Processes: The safety of passengers during maintenance and inspection procedures should be considered in designs. Identifying and correcting any risks or equipment failures that jeopardize passenger safety would be made easier through proper maintenance procedures, routine inspections, and adherence to safety regulations.

⦁ Security and Surveillance: To enhance passenger safety, all rolling stock equipment designs should include relevant and reliable safety features. To enable passengers to report any untoward incidents quickly, the location of emergency intercoms and emergency stop buttons should also be considered during the interiors and car body design.

⦁ Consistency: Design elements, such as controls, symbols, and terminology, should be consistent within the system or across similar systems. Consistency reduces cognitive load, promotes learning, and facilitates efficient and error-free interactions

Key HF Aspects Influencing Operator Safety in Rolling Stock Designs:

Human factors also have a significant impact on the performance of train drivers, station staff, and other employees in the rail network and can affect their productivity in several ways. The objective of incorporating human factor-centric designs into the safety management of systems in the railway network should be to ensure safe and easy-to-use equipment with increased reliability and efficiency, thereby preventing any human error while also improving employee working conditions in which they can discharge their duties efficiently. Human and individual characteristics, such as fatigue, stress, and other psychological factors like having to work on multiple tasks, frustration, anxiety, fear, and anger, affect job behavior that may impact safety and health and could significantly impair performance. To minimize these effects, it is essential to design the rolling stock and the work environment to be as safe and efficient as possible. The impact can be mitigated through a variety of measures in rolling stock systems design, such as

1)Workspace Design: Train Staff and operator workspace designs should consider the physical well-being of the users. This may include designing comfortable seating arrangements, adequate space for movement and posture, and optimizing the placement of controls and equipment to reduce physical strain and fatigue and improve drivers’ wellness and comfort, thus guaranteeing safer driving.

2) Visibility and Sightlines: Designing rolling stock with proper visibility is crucial for safety. To ensure that train drivers and station staff have clear views of the tracks, signals, and surroundings, human factors design should consider variables like window size, location, and form. A clear view makes it easier to see possible threats and improves situational awareness.

3) Noise and Vibration: Rail rolling stock operations often produce a lot of noise and vibration, which can affect the comfort and productivity of the operators. By adopting efficient insulation and vibration-dampening methods, human factor designs should seek to reduce noise and vibration levels. This lessens operator fatigue, enhances communication, and guarantees greater focus.

4) Human-Machine Interface (HMI): Human factors design should focus on optimizing the design of the HMI, which includes controls, displays, and other interfaces through which train drivers and operators interact with the rolling stock. The HMI should be designed to be user-friendly, providing operators with relevant and timely information, intuitive controls, and clear feedback. An effective HMI system for any passenger rail application should rely on reliable, consistent performance and controls that are clear to all passengers. Well-designed HMIs reduce the likelihood of operator errors and enhance situational awareness.

5) Training and Procedures: Designing efficient training programs and helping clear and concise operating procedures operators perform their duties diligently. Training should be able to address the specific cognitive and physical demands of the job, ensuring operators are adequately prepared. To lower the possibility of human mistakes and ensure safe operations, all the procedures should be clear, consistent, and simple to follow.

6) Fatigue Management: The design of rail equipment and systems should consider the impact of fatigue on operator performance and safety. It should include designing work schedules and rest periods to manage fatigue and prevent excessive tiredness. Rest areas and facilities for operators should also be designed to promote restful breaks.

7) Emergency Situations: The ability of operators to react appropriately in emergency scenarios should be considered during the design. These entail creating emergency controls, protocols, and training to guarantee operators can react swiftly and precisely to serious occurrences like derailments, collisions, or equipment failures.

Conclusion:

Human factor designs in Rail Rolling Stock systems should place a priority on safety by considering potential risks, offering the proper warnings and protections, and making sure that crucial activities or functions are shielded from accident activation or misuse. These approaches ensure that the rolling stock systems are designed with its target users in mind, leading to equipment and controls that are intuitive, ergonomic, and easy to operate, thereby reducing potential errors and improving safety aspects as well as effectiveness. By taking a human-centered approach to design, we can create a safer environment for passengers and staff on our railways.
At Quest Global, we strive to be the most trusted partner for the world’s hardest engineering problems. We are devoted to enhancing the safety of rail travel both on and off the track by utilizing our extensive industry experience and superior design capabilities. Our multidisciplinary team of engineers helps you with your new product designs with the highest level of safety.
Connect with our team of experts to learn more about how human factors design principles prioritize passenger safety in rail networks and train stock and how Quest Global’s innovative engineering solutions may help you improve passenger safety while minimizing time and expense.

Visit our website at https://www.quest-global.com/industries/rail/

References:

[1] Hammerl, M., Jäger, B., & K. Lemmer. (2008). An Integrated Model for Working Environments and Rail Human Factors. In D. de Waard, F. O. Flemisch, B. Lorenz, H. Oberheid, & K. A. Brookhuis (Eds.), Human Factors for Assistance and Automation (pp. 415 – 427). Maastricht: Shaker Publishing
[2] Clarke, T. (2005). The Ergonomics Programme at Network Rail. In J. R. Wilson, B. Norris, T. Clarke & A. Mills (Eds.), Rail Human Factors: Supporting the Integrated Railway (pp. 19 – 21): Ashgate.
[3] N.Bevan, J.Carter, J.Earthyu, T.Gies and S.Harker, “New ISO standards for usability, usability reports and usability measures,” Lecture Notes Computer Science, vol.9731, pp.268-278, 2016
[4] EN 50126-1:2017 Railway Applications – The Specification and Demonstration of Reliability, Availability, Maintainability and Safety (RAMS) – Part 1: Generic RAMS Process
[5] Human Factors in Engineering and Design / Mark S. Sanders, Ernest J. McCormick. -7th ed. ISBN 0-07-054901-X, McGraw-Hili, Inc