At this time, there are no (national and international) legal design requirements for ADAS and other ITS. There are, however, recommendations and general design principles focusing on safe use of ADAS/ITS. The European Commission’s recommendations about safe and efficient information and communication systems, dating from 2008 [13], are relevant. Section 4.3 of these recommendations sums up six groups of recommendations under the heading ‘Principles’ (overall design, installation, information presentation, interface with displays and control, system behaviour, and information about the system) and Section 5.2 sums up usage recommendations aimed at, for instance, employers and end-users. It would be taking things too far to mention them all here, but the overall design objectives present an appropriate framework for these principles.
They are:
- The system supports the driver and does not give rise to potentially hazardous behaviour by the driver or other road users
- The allocation of driver attention while interacting with system displays and controls remains compatible with the attentional demand of the driving situation
- The system does not distract or visually entertain the driver
- The system does not present information to the driver which results in potentially hazardous behaviour by the driver or other road users
- Interfaces and interface with systems intended to be used in combination by the driver while the vehicle is in motion are consistent and compatible
Annex 5 of a UNECE resolution dating from 2017 [14] gives information about the design principles for ADAS. There are three categories: ADAS that inform, ADAS that warn and ADAS that intervene (‘control systems’). The resolution only deals with the latter, divided into four sections.
- The control element: the requirement that the system intervenes autonomously in case of an inevitable crash, but that the driver may also intentionally ignore the system.
- The operation: the system is enabled by default, but the driver should also be allowed to turn it off (permanently).
- The principles for communication by means of the display: this should clearly show drivers whether the system is enabled and when they should take over full control of the vehicle.
- Additional information/communication elements: elements that remind the driver to be fully alert at all times, et cetera.
Older drivers are known to process information more slowly, to have poorer eyesight and hearing (see the archived SWOV fact sheet The elderly and Intelligent Transport Systems (ITS). Slower information processing implies, among other things, that the elderly may experience some problems if different ADAS are operational at the same time but function independently. Alignment or choice decisions are therefore important. Eyesight and hearing impairment imply that letters should be larger and that information should preferably be visible, audible and tangible at the same time and that the timing of the information should be attuned to the user’s reaction time. Since the capacities and limitations of the elderly differ greatly, customization is the ideal solution, which intelligent systems should be able to facilitate. In addition, it is important that ADAS applications should not only be tested by young drivers, but also by older ones. If older drivers are able to perform a task safely and with hardly any trouble, other drivers should be able to do so as well [15].
