This chapter analyses and discusses the needs, problems and limitations of various road users. The role of drivers has changed considerably, and now has less feedback and greater demands on attention, with higher speeds. Road users' operational goals and tasks include: (1) strategic tasks; (2) navigation; (3) road tasks; (4) speed control; (5) traffic tasks; (6) rule compliance; and (7) manoeuvring tasks. Drivers' physiological, psychological and sociological limitations need to be taken into account. Information technology (IT) has a very large potential for rationalising road transport, and many of its products are already available to help the driver. IT can support or even replace the driver in many critical situations. To a large extent, human factors will limit the safety effects of new IT-based systems. For example: (1) computerisation of road traffic needs to be acceptable to the public and road users; (2) the new equipment must not cause new problems to drivers, such as distraction and information overload; (3) drivers will use new measures for their own perceived interests; (4) advanced information systems will radically change drivers' situations and tasks; (5) the resulting simpler driving may lead to more frequent and longer journeys; (6) there will be a long delay before all vehicles have new IT-based systems; (7) the effects on road users outside vehicles should be addressed. The use of IT also has various safety advantages.
Abstract