Road Network Operations
& Intelligent Transport Systems
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Human Factors

Author Alan Stevens (TRL Ltd., UK)

Intelligent Transport Systems (ITS) can support road users in various ways, with information and warnings, and various levels of assistance and automation, depending on the service. Road users interact both with ITS and the wider transport system in complex and sometimes unpredictable ways. There is a need to understand fully the broader context, its dynamic characteristics and the role and responsibilities of its different stakeholders. It is only then that best results from any intervention will be obtained – with a high probability of user acceptance and adoption.

Human factors is the branch of science and technology that includes what is known and what is conjectured about human behaviour and biological characteristics. It can be applied to the specification and design of products and services – and their evaluation, operation and maintenance.

ITS technologies provide users with an interface – known as the Human Machine Interface or HMI. “Behind” the interface is the logic and software of the interaction which contributes greatly to its “look and feel”. Human Machine Interaction (also abbreviated to HMI) is a key component of human factors. Designing or choosing an HMI that is appropriate for the context of use (such as “while driving” or “at a bus stop”) can have a decisive effect on the outcome.

Proper attention to human factors can enhance the safety, effectiveness and ease of use of Intelligent Transport Systems and Services for individuals and for widely different groups of users. A key point is the variability within users – and within specific groups of users, such as “car drivers”, “pedestrians”, “Traffic Control Centre Operators” or a “Mobile Safety Patrol”. Users have different needs and motivations. For example, the task to be performed by a cyclist is very different from that of a control room operative or a road maintenance worker.

The importance of the broader road transport environment within which ITS informs and assists users requires an emphasis on “user-centred design”. It is important that road users are involved in ITS design. A complete understanding of the tasks they need to perform and their scope for error is vital. The importance of piloting, feedback and monitoring in any ITS or other transport system design, its introduction and its operation cannot be under-stated.

Relevant ITS standards for HMI cover areas such as vehicle design, the design of infrastructure (signage for example), standards for ITS in control rooms, for tunnel design and management, and for public transport. The needs of vulnerable road users are especially important here.

Ten things a Road Network Operator should know about Human Factors

The design of the Human Machine Interface (HMI) has to support the user and promote safety in the transport environment. The following provides some key advice based on human factors principles:

  • when a technical system such as ITS is introduced into a societal context, complexity is likely to emerge. Getting it right is not easy - consult human factors professionals where necessary
  • users of ITS come in all shapes and sizes and with different expectations and abilities. For example, older users of technology may have more difficulties than younger ones – so ITS should take account of this diversity
  • adopt a user-centred approach to design and introduction of ITS – the benefits outweigh the apparent upfront costs
  • find out the real needs of users. Simply automating what they currently do themselves may not be the best solution
  • involve actual users – but remember that they are individuals. Do not expect them all to behave the same
  • human error is inevitable – expect it, and develop ITS designs to reduce errors and mitigate their effects
  • use standards and guidelines where appropriate – they contain a wealth of knowledge and experience
  • always pilot before full implementation – this applies from simple questionnaires to complex real-time ITS
  • evaluate the ITS through trials in realistic contexts. Depending on results and feedback from users – you will probably need to adjust the system or service, or modify the context of use, to achieve the desired outcomes
  • set up mechanisms for monitoring ITS use and receiving feedback from users. They know, often better than you do, what works and what does not
  • These points may appear to be “common sense” but there are many examples of design and implementation of ITS where this common sense has clearly failed
Reference sources

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