Joint Optimisation of Rail Level Crossing Systems
In addition to the need to better understand the factors influencing user behaviour, we argued in Chapter 1 that the existing rail level crossing designs do not represent a jointly optimised system. Broadly speaking, there are three distinct design philosophies: technology-centric designs, human-centric designs and jointly optimised designs. Technology-centric designs are characterised by the introduction of new technologies where human activities are required to adapt to the technology. Conversely, human-centric designs are characterised by the introduction of new working practices, for which technologies are brought into support. In contrast, jointly optimised designs occur where design is used to enable successful performance to emerge from the interaction between human and technological aspects of the system. Essentially, the human and technological systems are considered together and are designed to be synergistic.
Existing rail level crossing environments are typically technology-centric. Here, the interaction fundamentally relies upon road users becoming aware of warnings provided to signal an upcoming level crossing (passive crossing) or an approaching train (active crossing) and complying with legislated requirements to stop and give way to approaching trains. This is a rigid system, based heavily in technology (both the physical sense and the abstract sense in the form of rules), that leaves little room for flexibility or adaptation. Indeed, even the existing process for re-designing level crossings is technology-focussed, through the application of engineering standards. The only existing intervention to the authors’ knowledge that could be considered a social intervention is education and awareness campaigns, but even here the focus is typically on educating users about the rules governing their behaviour at crossings, not about positive social outcome for users themselves.
The Cognitive Work Analysis Design Toolkit (CWA-DT) design process changed this focus. The process itself was socially based - a participatory group process where stakeholders and subject-matter experts shared knowledge and expertise and worked collaboratively to develop novel ideas. This broadened the design space beyond the application of engineering standards to explore new opportunities for system functioning. In addition, several tools used within the design process were specifically focussed on priming participants to consider the social aspects of rail level crossing functioning. For example, scenarios and personas were intended to better engender a sense of empathy with different types of road users. In addition, the consideration of sociotechnical systems theory values and how they can be applied within rail level crossing design was intended to re-focus design efforts on the needs of humans within the system, including opportunities for designing transport systems that support the quality of life of their users.
This sociotechnical systems theory-inspired design process generated several designs (or aspects of designs) that were more human-centric in nature. These included the following:
- • The removal of existing warning technologies and replacement with human supervisors in the Community Courtyard crossing.
- • The use of a shared space road design on approach to the Community Courtyard crossing that prioritises active transport.
- • Slowing of road vehicles and/or trains in the Community Courtyard, Simple But Strong and Ecological Interface Design crossing concepts, which was intended to provide vehicle operators, especially train drivers, with more control in emergency situations.
- • The support for social interaction and knowledge sharing intended by the inclusion of cafes and community hubs in the Community Courtyard crossing.
- • The scheduling of regular forums in regional areas to facilitate discussions between truck drivers, train drivers and system stakeholders about safety issues at level crossings and build empathy, as part of the GPS Average Speed concept.
When considering the six novel rail level crossing concepts as whole designs, it is possible to categorise them as either technology-centric, human-centric or jointly optimised designs. This is represented in Figure 11.2, which shows the extent to which the different designs produced in this research programme align with the three design philosophies.
As shown in Figure 11.2, the Ecological Interface Design crossing is the concept best aligned with the jointly optimised design philosophy. The Ecological Interface Design crossing uses minimal technology and attempts to optimise the interaction between road users and trains by clarifying or amplifying the important constraints such as the train, drivers’ speed and the proximity of the train to the crossing. The Comprehensive Risk Control crossing, conversely, is the most technology-centric concept, as it uses various forms of technology to attempt to control road user behaviour. This includes boom gates, in-road LED lights, pedestrian gates and adaptive bollards. By comparison, the Community Courtyard crossing, shown at the bottom of Figure 11.2, is the most human-centric of the designs. The Community Courtyard crossing does not use active warnings at the crossing; instead, it implements a shared space concept whereby human interactions are relied upon for safe performance.
FIGURE 11.2 The alignment of rail level crossing design concepts with design philosophies. CC, Community Courtyard crossing; Comp, Comprehensive Risk Control crossing; EID, Ecological Interface Design crossing; GPS, GPS Average Speed interface; ILC, Intelligent Level Crossing; SbS, Simple But Strong crossing.