200 research outputs found
Testing automated driving systems to calibrate drivers’ trust
Automated Driving Systems (ADSs) offer many potential benefits like improved safety, reduced traffic congestion and lower emissions. However, such benefits can only be realised if drivers trust and make use of such systems. The two challenges explored in this thesis are: 1) How to increase trust in ADSs? 2) How to identify the test scenarios to establish the true capabilities and limitations of ADSs?
Firstly, drivers’ trust needs to be calibrated to the “appropriate” level to prevent misuse (due to over trust) or disuse (due to under trust) of the system. In this research, a method to calibrate drivers’ trust to the appropriate level has been created. This method involves providing knowledge of the capabilities and limitations of the ADSs to the driver.
However, there is a need to establish the capabilities and limitations of the ADSs which form the knowledge to be imparted to the driver. Therefore, the next research contribution lies in the development of a novel method to establish the knowledge of capabilities and limitations of ADSs (used to calibrate trust) in a reliable manner. This knowledge can be created by testing ADSs. However, in literature, an unanswered research question remains: How to identify test scenarios which highlight the limitations of ADSs? In order to identify such test scenarios, a novel hazard based testing approach to establish the capabilities and limitations of ADSs is presented by extending STPA (a hazard identification method) to create test scenarios. To ensure reliability of the hazard classification (and of the knowledge), the author created a novel objective approach for risk classification by creating a rule-set for risk ratings.
The contribution of this research lies in developing a method to increase trust in ADSs by creating reliable knowledge using hazard based testing approach which identifies how an ADS can fail
The role of human operators in safety perception of av deployment—insights from a large european survey
Autonomous vehicles are anticipated to play an important role on future mobility offering encouraging solutions to today’s transport problems. However, concerns of the public, which can affect the AVs’ uptake, are yet to be addressed. This study presents relevant findings of an online survey in eight European countries. First, 1639 responses were collected in Spring 2020 on people’s commute, preferred transport mode, willingness to use AVs and demographic details. Data was analyzed for the entire dataset and for vulnerable road users in particular. Results re-confirm the long-lasting discourse on the importance of safety on the acceptance of AVs. Spearman correlations show that age, gender, education level and number of household members have an impact on how people may be using or allowing their children to use the technology, e.g., with or without the presence of a human supervisor in the vehicle. Results on vulnerable road users show the same trend. The elderly would travel in AVs with the presence of a human supervisor. People with disabilities have the same proclivity, however their reactions were more conservative. Next to safety, reliability, affordability, cost, driving pleasure and household size may also impact the uptake of AVs and shall be considered when designing relevant policies
Road safety management capacity review
Introduction
Study Context
Following on from the government’s manifesto to an annual reduction in road deaths and injuries, the
British Road Safety Statement 2015 (BRSS) set out the government’s commitment to invest further in
continuing road safety activity, and to conduct a Road Safety Management Capacity Review (RSMCR).
A RSMCR is a strategic assessment, benchmarking and capacity building tool, originally developed by
the World Bank's Global Road Safety Facility, to guide investments and assist countries in
strengthening road safety management. It is recommended for use by the OECD/International
Transport Forum and the World Road Association as a first step in further developing and extending
effective Safe System investment strategies, plans and projects in all countries and contexts.
In May 2017, the DfT commissioned a RSMCR to benchmark and understand the current status of
institutional delivery of road safety in Britain, and to identify practical and actionable opportunities for
strengthening joint working, local innovation, and efficiency on a national and local basis.
Safe System
The overarching theme of the BRSS is the government’s adoption of the recommended Safe System
approach to preventing death and serious injuries in road collisions. Its application is cited as a key
national priority in the UK. While building on current practice, some re-alignment in national road
safety focus and activity will be necessary over time. Safe System implementation towards zero deaths
and serious injuries is a long-term project and is in different stages of development in different
countries and jurisdictions.
Safe System comprises both an explicit goal and strategy. The long-term Safe System goal is for the
ultimate prevention of deaths and serious injuries, through incremental targeted improvements within
a specified safety performance framework. The Safe System strategy aims for a more forgiving road
system that takes human fallibility and vulnerability into account. The road traffic system is planned,
designed, operated and used such that people are protected from death and serious injury in road
collisions.
Aims and Objectives of the Review
The overarching aim of the RSMCR is to identify practical and actionable opportunities for
strengthening joint working, local innovation, and efficiency on a national and local basis. In particular
the RSMCR seeks to understand the current status of institutional delivery of road safety in Britain by:
Examining national, regional and local structures, responsibilities, accountabilities, relationships
and coordination;
Examining whether management effort and resources at all levels are being targeted effectively
at designing, and enabling or delivering evidence-based interventions and initiatives that can
have the greatest impact in preventing and reducing the number of road users killed and
seriously injured;
Assessing the current road safety delivery landscape against the Safe System road safety
management assessment framework and determining whether there is an imbalance in
resource effort for each element and at each level (national, regional and local);
Investigating how institutional capacity can be cost-effectively strengthened, within the context
of the BRSS, to deliver a Safe System approach to road safety; and
Identifying areas and means for improved joint working, local innovation and efficiency
Prediction of drivers’ performance in highly automated vehicles
Purpose: The aim of this research was to assess the predictability of driver’s response to critical hazards during the transition from automated to manual driving in highly automated vehicles using their physiological data.Method: A driving simulator experiment was conducted to collect drivers’ physiological data before, during and after the transition from automated to manual driving. A total of 33 participants between 20 and 30 years old were recruited. Participants went through a driving scenario under the influence of different non-driving related tasks. The repeated measures approach was used to assess the effect of repeatability on the driver’s physiological data. Statistical and machine learning methods were used to assess the predictability of drivers’ response quality based on their physiological data collected before responding to a critical hazard. Findings: - The results showed that the observed physiological data that was gathered before the transition formed strong indicators of the drivers’ ability to respond successfully to a potential hazard after the transition. In addition, physiological behaviour was influenced by driver’s secondary tasks engagement and correlated with the driver’s subjective measures to the difficulty of the task. The study proposes new quality measures to assess the driver’s response to critical hazards in highly automated driving. Machine learning results showed that response time is predictable using regression methods. In addition, the classification methods were able to classify drivers into low, medium and high-risk groups based on their quality measures values. Research Implications: Proposed models help increase the safety of automated driving systems by providing insights into the drivers’ ability to respond to future critical hazards. More research is required to find the influence of age, drivers’ experience of the automated vehicles and traffic density on the stability of the proposed models. Originality: The main contribution to knowledge of this study is the feasibility of predicting drivers’ ability to respond to critical hazards using the physiological behavioural data collected before the transition from automated to manual driving. With the findings, automation systems could change the transition time based on the driver’s physiological state to allow for the safest transition possible. In addition, it provides an insight into driver’s readiness and therefore, allows the automated system to adopt the correct driving strategy and plan to enhance drivers experience and make the transition phase safer for everyone.</div
Effort reduction and collision avoidance for powered wheelchairs : SCAD assistive mobility system
The new research described in this dissertation created systems and methods to assist wheelchair users and provide them with new realistic and interesting driving opportunities. The work also created and applied novel effort reduction and collision avoidance systems and some new electronic interactive devices. A Scanning Collision Avoidance Device (SCAD) was created that attached to standard powered wheelchairs to help prevent children from driving into things. Initially, mechanical bumpers were used but they made many wheelchairs unwieldy, so a novel system that rotated a single ultra-sonic transducer was created. The SCAD provided wheelchair guidance and assisted with steering. Optical side object detectors were included to cover blind spots and also assist with doorway navigation. A steering lockout mode was also included for training, which stopped the wheelchair from driving towards a detected object. Some drivers did not have sufficient manual dexterity to operate a reverse control. A reverse turn manoeuvring mode was added that applied a sequential reverse and turn function, enabling a driver to escape from a confined situation by operating a single turn control. A new generation of Proportional SCAD was created that operated with proportional control inputs rather than switches and new systems were created to reduce veer, including effort reduction systems. New variable switches were created that provided variable speed control in place of standard digital switches and all that research reduced the number of control actions required by a driver. Finally, some new systems were created to motivate individuals to try new activities. These included a track guided train and an adventure playground that including new interactive systems. The research was initially inspired by the needs of young people at Chailey Heritage, the novel systems provided new and more autonomous driving opportunities for many powered wheelchair users in less structured environments.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Constructing pedestrian-centric street mobility: Observation and simulation for design
There are three principal components to the research presented in this thesis: a video-observation study of pedestrian behaviours and interactions with traffic, leading to the development of an agent-based digital simulation, and demonstrating the potential of this simulation for designing pedestrian-centric interventions in the streetscape. The long-term objective is to devise streetscapes that responsively adapt to the needs of pedestrians.
Since the advent of car culture in the late 1930s, the approaches to street design have prioritised efficient motorised traffic flow, restricting walking and neglecting the pedestrian point of view. In recent years, however, a growing interest in making urban spaces more pedestrian-friendly has emerged, popularising concepts such as walkability, shared space, and traffic calming. These approaches aim to promote active travel and reduce car dependency in order to mitigate congestion, pollution, accidents and other harms.
Urban studies have concentrated primarily on pedestrian-only zones and utilised spatial features as a way to reach pedestrian-friendly streets. Meanwhile, transport studies have tended to approach the street from a throughput and vehicle-oriented stance. Despite these endeavours, pedestrian-oriented approaches appear to lack systematic consideration of pedestrian behaviours as they interact with motor vehicles and street infrastructure. My PhD research differs from prior studies by focusing on these behaviours and interactions to support a pedestrian-oriented street mobility system.
The current design of streets communicates to pedestrians via its structures and signs, such as barriers, crossings, and lights, while its capacity to respond and adapt is minimal. In contrast, this thesis argues that, since the street environment is inherently dynamic, we should analyse its dynamics and design the street to be responsive. Through responsiveness, my aim is to increase the convenience of pedestrian movement whilst creating a safe experience.
This PhD asks the question 'how to design a pedestrian-centric street system that dynamically manages street mobility?'. The research takes a practice-based and reflective approach, designing agent-based simulations based on a qualitative observational study. Designing a simulation accomplishes two things: 1) it creates a space for implementing and evaluating possible design interventions, and 2) it prompts new insights into the behavioural processes of pedestrians. My research has followed an iterative cycle in line with second-order cybernetics: in two feedback loops, the first study informed the second study while the second informed the first.
The video observation of street behaviours particularly explored pedestrian decision and interaction processes, identifying pedestrians’ own observational strategies and their varying levels of risk-taking. These aspects are reflected in the simulation.
The first chapter introduces the pedestrian issues on the street and sets out the key concepts in pedestrian-centric street design. The second chapter examines the literature and existing practice that addresses pedestrian and vehicle interactions on the street. Chapter three sets out the theoretical framework and the following chapter describes the methodology. The three subsequent chapters present the following studies: (1) understanding the context by conducting qualitative video observation in a real street environment to observe and document the relations between streets, pedestrians and vehicles; (2) creating an artificial pedestrian society for simulation purposes, using agent-based modelling, both to refine the understanding developed through video analysis and to create a platform for experimentation; (3) design and implementation of prototype responsive interventions within the simulation, focusing on localised changes in the environment to empower pedestrians. The last chapter reflects on these projects by discussing the research contributions in terms of methods, techniques, and practices. The methodological innovation includes combining qualitative and computational tools as well as the use of simulation and video analysis in an iterative and reflexive cycle. Theoretical contributions include evaluating streets through pedestrian dynamics, creating a taxonomy of existing pedestrian interventions according to their spatial and temporal impacts, and rethinking the street as a responsive environment. The practical component advances the technical state of the art by expanding the capabilities of pedestrian agents when negotiating with vehicles and making crossing decisions and demonstrates the potential for designing novel interventions in the streetscape, including those that respond to pedestrian behaviour. The last chapter, also, emphasises the role of reflective design practice and the place of simulation within it
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