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Abstract
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Road safety initiatives over the years have been heralded by concepts such as behavioural issues, new safety features in vehicles and road improvement projects. These have progressively reduced the road toll by targeting high priority issues, but without new directions the initiatives may have diminishing returns over time. Furthermore, it is well known to engineers that holistic and system wide approaches such as Vision Zero are fundamentally more powerful as they target elimination with a coordinated approach to the problem rather than progressive reduction with isolated actions. This paper identifies the concept of “Interface Design” as a potential catalyst for the next major advances in road safety. Interface Design is a holistic approach which encourages players in the development of systems to consider all possible interfaces of their project. The authors show some examples of interface design and in the process hope to highlight how this design and engineering approach represents a new frontier.
Interface design occurs at three main levels: 1. Behavioural interfaces. Interface design when applied to the vehicle operator is concerned with vehicle control and crash avoidance by the vehicle operator or independently. This includes the gamut of behavioural issues, including: the fundamentals of driver attitudes and training; the area of ergonomic and human factors (manmachine interface); in-vehicle systems interfaces (GPS, mobile phones etc.); vehicle control systems (such as ABS, ESC etc.); and through to the interaction with the road environment (road design, signage etc.), and other road users (other vehicles, cyclists, motorcyclists, pedestrians, etc.). Operator vigilance and effects of alcohol, drugs and fatigue as well as personal factors must also be considered. Similarly motorcyclists, bicyclists and pedestrians are faced with a range of interface issues regarding their behaviour in traversing the road transport system.
2. Vehicles and Road interfaces. This relates to the opportunity available in the road transport system for collisions of all sorts. Interface design for vehicle crashworthiness includes vehicle-to-vehicle crashes as well as compatibility with heavy vehicles and road infrastructure, level- crossings and so on. An example of a typically effective road-vehicle-driver interface design is the roundabout. This provides an effective interface for vehicles changing direction at an intersection, as it reduces both crash risk and injury risk due to the intersection design and reducing driver vehicle speeds (in the form of reduced conflicts, simplified driver decision making, reduced crash speeds). Another example is heavy vehicle design where energy-absorbing underrun barriers are fitted which provide an improved geometric and stiffness interface in crashes with other vehicles or other road users.
3. Human-impact interface. Injury prevention in a crash is a function of the interface between the human and whatever is impacted or restrains the human during an impact. In this sense, we need to differentiate the macro (vehicle) level impact interface from the micro (human – object contact or restraint) level interface where injury actually arises. For example, at the macro level we are concerned with maintenance of vehicle structure and occupant compartment integrity as key criteria, such that the human-vehicle-outside environment interface is kept viable. At the micro level, safety systems such as airbags typically provide an interface between a person’s head and vehicle internal (e.g. front airbag and steering wheel) or external (e.g. side airbag and pole) structure. Airbags provide both very good load distribution and good deceleration or ‘crush’ characteristics. On the other hand for pedestrians, the micro level can be important such as head impact with a steel bull bar fitted to the front of a truck or car, with such structures representing an incompatible interface. |