Hello everyone, and welcome to my presentation on our paper: A Taxonomy of Vulnerable Road Users for
HCI Based On A Systematic Literature Review I am Mark Colley from Ulm University.
With automated vehicles, traffic will change both for users within the vehicle
as well as for other road users sharing the street. With this change, novel challenges arise.
For example, one question currently addressed is whether
automated vehicles need to be able to communicate with vulnerable road users and,
if they do, how this should be done.
This means that, for example, an automated vehicle unambiguously
communicates its intent to people wanting to cross the street in front of them. Numerous
concepts and modalities seem possible and have already been evaluated.
However, not every modality and every concept is appropriate for the diverse
set of possible addressees. In the context of external communication of automated vehicles,
the addressees include children, older people,
people with disabilities, and every other imaginable road user.
During our research on precisely this topic, we stumbled across the usage of the term "vulnerable
road users" as a possible target group. Authors used the terminology either in accordance with the
definition of the World Health Organization, as a synonym for pedestrian, or else wise.
Thus, while using the same terminology, actually, different groups were addressed by their concepts.
We argue that the current definitions are too broad to be applied to design
a single human-computer interaction concept or application.
Therefore, we propose a novel taxonomy. For this, we first conducted a systematic literature review
with regards to the usage of the term vulnerable road users.
Here, you can see our search query, the venues we searched, and the time frame applied.
We found that most work addresses pedestrians or cyclists only,
10.71% address pedestrians and cyclists together.
Still, we found work focusing on children, older people, and people with impairments.
Based on the literature analysis and the found addressees,
we constructed our taxonomy for vulnerable road users in two parts.
The first part of the proposed taxonomy indicates how to proceed from general applications to
specific user groups or users with four layers. The subgroups are ordered from the left,
where the vulnerable road users are slow, to the right, where the vulnerable road users are fast.
The second part describes specific attributes of Especially Vulnerable Road Users (EVRUs) with
three layers. This is designed as an attribute and can be assigned to any of the vulnerable
road user categorizations from layer four (presented in orange). Therefore, it supports
a precise specification of sub-groups.
In our opinion, the missing of specified target groups, especially in the field of
external communication of automated vehicles, is a long-overdue discussion since vulnerable
road users and these communication concepts are a trending topic of the last years.
We believe that researchers and practitioners in the automotive
and traffic domain will benefit from a clear and structured definition of
vulnerable road users while still remaining a useful granularity.
While we believe that our taxonomy's main
application area will be for external communication of automated vehicles,
it is targeted towards the broader field of Human-Computer Interaction.
At least, we hope to provide a solid starting point for some of the processes
both in academia and industry when debating and creating novel interaction concepts.
Overall, this work highlights the need to precisely specify target groups for prototype
development and inclusion in the automotive domain. The introduced taxonomy provides a basis
for the precise use of keywords. It could improve the comparability of prototypes,
the understanding of the scope of investigations,
and the description of target groups in automotive research and practice.
Thank you for your attention!