Designers often build technical systems without completely understanding the tasks to be performed. Intelligent Transport Systems (ITS) need to be designed to be both useful and usable. Being usable is not enough if the system is not first useful. Users of ITS are diverse individuals – they do not all think the same way and they can be inconsistent and unpredictable. (See Diversity of Users)
It is not surprising that it is often difficult for the designers of technology to understand exactly the real needs of their potential users, how the technology will be used and how use will change as familiarity with the system or service develops. This is particularly the case for complex systems such as ITS in the broader transport context. The goal of good design is for complexity to be made to appear simple or intuitive to its users.
The complexity of ITS processes and their dynamics makes it essential to use sound design principles for robustness. For this reason, ITS require feedback of information from different process states using appropriate sensors. The feedback will also provide the input to adaptive control algorithms for decision-making by users – and make the processes less sensitive to disturbances. The complex nature of transport systems involving the interaction of many different systems and services is clear from the information feedback loops and the varied timescales used in the different decision-making processes.
Human error becomes virtually inevitable with the large number of different links and connections in the networks and processes of modern transport systems. In the transport domain one of the most critical situations is that of driver-vehicle interaction – as mistakes, slips and lapses in the primary driving tasks will have safety implications. (See Human Performance)
As well as reducing critical errors, there are many other practical reasons for involving users:
The overall message is that ITS should not be designed, developed or introduced without involving those who must use it. A holistic approach is required which acknowledges and accounts for the interactions between ITS and its users.