Natasha Merat

Natasha Merat
University of Leeds · Institute for Transport Studies (ITS)

BSc, PhD
Investigating the interaction of humans, as drivers and pedestrians, with automated vehicles

About

260
Publications
115,140
Reads
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6,993
Citations
Citations since 2017
193 Research Items
5960 Citations
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
Additional affiliations
November 2013 - July 2016
University of Leeds
Position
  • Professor (Associate)

Publications

Publications (260)
Preprint
Full-text available
As safe and comfortable interactions with pedestrians could contribute to automated vehicles' (AVs) social acceptance and scale, increasing attention has been drawn to computational pedestrian behavior models. However, very limited studies characterize pedestrian crossing behavior based on specific behavioral mechanisms, as those mechanisms underpi...
Preprint
Full-text available
The deployment of automated vehicles (AVs) has generated high societal expectations. However, due to the absence of the driver role, the communication issues between pedestrians and AVs have not yet been solved. Previous research has shown the crucial role of implicit signals in this context. However, it is still unclear how pedestrians subjectivel...
Preprint
Full-text available
Automated driving needs to be comfortable to encourage the broad acceptance and usage of automated vehicles (AVs). However, current research provides limited knowledge on the descriptions and influencing factors of user comfort in automated driving, especially from the perspective of an AV’s driving styles. This paper presents results from an onlin...
Article
The removal of drivers' active engagement in driving tasks can lead to erratic gaze patterns in SAE Level 2 (L2) and Level 3 (L3) automation, which has been linked to their subsequential degraded take-over performance. To further address how changes in gaze patterns evolve during the take-over phase, and whether they are influenced by the take-over...
Preprint
Full-text available
Augmented Reality (AR) technology could be utilised to assist pedestrians to navigate safely through traffic. However, whether potential users would understand and use such AR solutions is currently unknown. Nine novel AR interfaces for pedestrian-vehicle communication, previously developed using an experience-based design method, were evaluated th...
Conference Paper
Driver distraction is known to be a potential risk factor for traffic safety. Previous studies have shown that increased cognitive load can affect many driving outcomes, and lab-based studies have commonly used the detection response task (DRT) to quantify the level of cognitive load from in-vehicle systems during driving. The aim of the present st...
Article
Full-text available
Accidents involving pedestrians are particularly common at unsignalised intersections and mid-block crosswalks, where vehicles often do not yield to them. Analysing and understanding pedestrian crossing behaviour at such locations is vital for improving road safety. Previous studies have repeatedly shown that pedestrians tend to accept smaller t...
Article
Achieving optimal performance in human-machine systems, such as highly automated vehicles, relies, in part, on individuals’ acceptance and use of the system, which is in turn affected by their enjoyment of engaging with, or experiencing, the system. This driving simulator study investigated individuals’ real-time subjective evaluation of four diffe...
Article
Full-text available
Distractions have been recognised as one important factor associated with pedestrian injuries, as the increasing use of cell phones and personal devices. However, the situation is less clear regarding the differences in the effects of visual-manual and auditory-cognitive distractions. Here, we investigated distracted pedestrians in a one-lane road...
Preprint
Full-text available
One of the current challenges of automation is to have highly automated vehicles (HAVs) that communicate effectively with pedestrians and react to changes in pedestrian behaviour, to promote more trustable HAVs. However, the details of how human drivers and pedestrians interact at unsignalised crossings remain poorly understood. We addressed some a...
Preprint
Full-text available
This methodology paper proposes a novel and rapid automated motion artefact detection algorithm for electrodermal activity (EDA) data in dynamic environments. Building on a well validated shape-based artefact detection method, we improved the detection algorithm by adding an additional slope constraint. We also proposed a novel approach to account...
Article
Full-text available
Objective This study investigated users’ subjective evaluation of three highly automated driving styles, in terms of comfort and naturalness, when negotiating a UK road in a high-fidelity, motion-based, driving simulator. Background Comfort and naturalness play an important role in contributing to users’ acceptance and trust of automated vehicles...
Preprint
Full-text available
Previous research has shown that the use of an eHMI can lead pedestrians to make earlier, and more, crossing decisions in front of an AV. However, there has been little exploration of the impact of crossing infrastructure or AV approach direction on pedestrian behaviour. This CAVE-based pedestrian simulator study investigated the individual, and co...
Article
The goal of this paper was to measure the effect of Human-Machine Interface (HMI) information and guidance on drivers' gaze and takeover behaviour during transitions of control from automation. The motivation for this study came from a gap in the literature, where previous research reports improved performance of drivers' takeover based on HMI info...
Preprint
Interaction between road users is a societally important special case of human interaction, and a better understanding of such interactions is a key missing enabler for wide deployment of automated vehicles. Empirical studies implicate a variety of cognitive mechanisms, but these are studied and modeled in separate subfields of psychology. Here, we...
Preprint
Full-text available
Distractions have been recognised as one important factor associated with pedestrian injuries, as the increasing use of cell phones and personal devices. However, the situation is less clear regarding the differences in the effects of visual-manual and auditory-cognitive distractions. Here, we investigated distracted pedestrians in a one-lane road...
Conference Paper
Full-text available
This paper compared two different methodologies, used in two driving simulator studies, for real-time evaluation of comfort imposed by the driving style of different Automated Vehicle (AV) controllers. The first method provided participants with two options for assessing three different AV controllers. Participants rated each controller in terms of...
Preprint
Full-text available
This paper compared two different methodologies, used in two driving simulator studies, for real-time evaluation of comfort imposed by the driving style of different Automated Vehicle (AV) controllers. The first method provided participants with two options for assessing three different AV controllers. Participants rated each controller in terms of...
Article
Full-text available
This driving simulator study, conducted as a part of Horizon2020-funded L3Pilot project, investigated how different car-following situations affected driver workload, within the context of vehicle automation. Electrocardiogram (ECG) and electrodermal activity (EDA)-based physiological metrics were used as objective indicators of workload, along wit...
Article
Full-text available
The L3Pilot project tested SAE Level 3 (L3) conditionally automated driving functions addressing driving and travel behaviour, impacts on safety, efficiency, environment and socio-economics, and user acceptance. To investigate individual variance in acceptance of conditionally automated cars, an online survey was performed among 18,631 respondents...
Conference Paper
In SAE Level 2 (L2) and Level 3 (L3) automated driving, drivers are required to take over control from automation when reaching system boundaries. The length of time budget is the vital parameter that needs to be determined to ensure a safe takeover manner. Existing literature on this issue rarely considers potential interactions between time budge...
Preprint
Full-text available
This Horizon2020-funded driving simulator-based study on automated driving investigated the effect of different car-following scenarios, and takeover situations, on drivers’ mental workload, as measured by eye tracking-based metrics of pupil diameter and self-reported workload ratings. This study incorporated a mixed design format, with 16 drivers...
Preprint
Full-text available
Accidents involving pedestrians are particularly common at unsignalised intersections and mid-block crosswalks, where vehicles often do not yield to them. Analysing and understanding pedestrian crossing behaviour at such locations is vital for improving road safety. Previous studies have repeatedly shown that pedestrians tend to accept smaller time...
Conference Paper
Highly automated vehicles (HAVs) will need to interact with pedestrians in a safe and efficient way. Thus, investigating and modeling vehicle-pedestrian interactions at uncontrolled locations is essential to ensure safety and acceptance of these vehicles. Controlled studies are a valuable tool for these scenarios where all the tasks are not possibl...
Article
The impact of automated vehicles (AV) on pedestrians’ crossing behavior has been the topic of some recent studies, but findings are still scarce and inconclusive. The aim of this study is to determine whether the drivers’ presence and apparent attentiveness in a vehicle influences pedestrians’ crossing behavior, perceived behavioral control, and pe...
Article
Full-text available
Introduction: In current urban traffic, pedestrians attempting to cross the road at un-signalized locations are thought to mostly use implicit communication, such as deceleration cues, to interpret a vehicle's intention to yield. There is less reliance on explicit driver- or vehicle-based messages, such as hand/head movements, or flashing lights/b...
Article
Full-text available
A number of studies have investigated the acceptance of conditionally automated cars (CACs). However, in the future, CACs will comprise of several separate Automated Driving Functions (ADFs), which will allow the vehicle to operate in different Operational Design Domains (ODDs). Driving in different environments places differing demands on drivers....
Article
Full-text available
There is evidence that drivers’ behaviour adapts after using different advanced driving assistance systems. For instance, drivers’ headway during car-following reduces after using adaptive cruise control. However, little is known about whether, and how, drivers’ behaviour will change if they experience automated car-following, and how this is affec...
Technical Report
Full-text available
This deliverable presents the results of the Technical and Traffic Evaluation, and the User and Acceptance Evaluation of the L3Pilot project. For these evaluations, vehicle and questionnaire data were collected during the piloting operations of automated driving functions (ADFs) in L3Pilot. Results were generated separately for different types of A...
Technical Report
Full-text available
One of the main objectives of the L3Pilot was the large-scale piloting of Automated Driving Functions (ADFs) with a focus on level 3 functions. Since the development of ADFs, especially at SAE L3, is fairly well progressed, the aim was to pilot the functions, and to study user preferences, reactions and willingness to use vehicles equipped with AD...
Technical Report
Full-text available
The deliverable “D7.2 L3/L4 long-term study about user experiences” describes work within L3Pilot that investigated the change of user experience with long-term usage of an ADF. In the literature, this topic is summarised under the broader concept of behavioural adaptation. During the project it turned out that there are unanswered questions regard...
Preprint
Full-text available
Highly automated vehicles (HAVs) will need to interact with pedestrians in a safe and efficient way. Thus, investigating and modeling vehicle-pedestrian interactions at uncontrolled locations is essential to ensure safety and acceptance of these vehicles. Controlled studies are a valuable tool for these scenarios where all the tasks are not possibl...
Preprint
Full-text available
This distributed simulator study investigated pedestrians’ head-turning behaviour during a series of road crossings in a CAVE-based pedestrian simulator. Pedestrians were required to cross the road in front of an approaching vehicle, the kinematic behaviour of which was either programmed by the simulation to depict an automated vehicle (AV) or cont...
Article
Full-text available
Human behavior and interaction in road traffic is highly complex, with many open scientific questions of high applied importance, not least in relation to recent development efforts toward automated vehicles. In parallel, recent decades have seen major advances in cognitive neuroscience models of human decision-making, but these models have mainly...
Article
The development of Shared Automated Vehicles (SAVs) is well underway to provide mobility as a service (MaaS) and bring benefits such as reduced traffic congestion, reduced reliance on privately owned vehicles and increased independence to non-drivers. To realise the benefits of SAVs, adoption by private vehicle users is crucial. Previous research h...
Conference Paper
Full-text available
The future urban environment may consist of mixed traffic in which pedestrians interact with automated vehicles (AVs). However, it is still unclear how AVs should communicate their intentions to pedestrians. Augmented reality (AR) technology could transform the future of interactions between pedestrians and AVs by offering targeted and individualiz...
Conference Paper
Full-text available
Ambient LED displays have been used to provide peripheral light-based cues to drivers about a vehicle's current state, along with providing requests for a driver's attention or action. However, few studies have investigated the use of an ambient LED display to improve drivers' trust, perceived safety, and reactions during L3 automated driving. Due...
Poster
Full-text available
Pedestrian-AV interactions: This provides an overview of our latest publications within interACT (2020-2021).
Article
The successful deployment of automated vehicles (AVs) will depend on their capacity to travel within a mixed traffic environment, adopting appropriate interaction strategies across different scenarios. Thus, it is important to gain a detailed understanding of the specific types of interactions that are most likely to arise. The overall purpose of t...
Preprint
The impact of automated vehicles (AV) on pedestrians’ crossing behavior has been the topic of some recent studies, but findings are still scarce and inconclusive. The aim of this study is to determine whether the drivers’ presence and apparent attentiveness in a vehicle influences pedestrians’ crossing behavior, perceived behavioral control, and pe...
Article
Car-following is an important driving behaviour for intelligent vehicles and has a significant impact on traffic efficiency and traffic safety. Car-following models are widely developed to characterize the human-drivers car-following manoeuvre actions and adopted in traffic simulation and automated vehicle control system development. Car-following...
Preprint
Full-text available
This driving simulator study, conducted as a part of Horizon2020-funded L3Pilot project, investigated how different car-following situations affected driver workload, within the context of vehicle automation. Electrocardiogram (ECG) and electrodermal activity (EDA)-based physiological metrics were used as objective indicators of workload, along wit...
Preprint
This driving simulator study, conducted as a part of Horizon2020-funded L3Pilot project, investigated how different car-following situations affected driver workload, within the context of vehicle automation. Electrocardiogram (ECG) and electrodermal activity (EDA)-based physiological metrics were used as objective indicators of workload, along wit...
Article
Full-text available
Reducing car dependency supports the creation of a more sustainable transport system. However, automated vehicles (AVs) are predicted to increase the attractiveness of car travel and decrease the use of public transport and active travel. This current study explored how travellers’ intention to use AVs and their current travel behaviour influence t...
Preprint
Full-text available
Objective: This study investigated users’ subjective evaluation of three highly automated driving styles, in terms of comfort and naturalness, when negotiating a UK road in a high-fidelity, motion-based, driving simulator. Background: Comfort and naturalness are thought to play an important role in contributing to users’ acceptance and trust of au...
Preprint
Achieving optimal performance in human-machine systems, such as highly automated vehicles, relies, in part, on individuals’ acceptance and use of the system, which is in turn affected by their enjoyment of engaging with, or experiencing, the system. This driving simulator study investigated individuals’ real-time subjective evaluation of four diffe...
Preprint
Full-text available
The future urban environment may consist of mixed traffic in which pedestrians interact with automated vehicles (AVs). However, it is still unclear how AVs should communicate their intentions to pedestrians. Augmented reality (AR) technology could transform the future of interactions between pedestrians and AVs by offering targeted and individualiz...
Preprint
Full-text available
The successful deployment of automated vehicles (AVs) will depend on their capacity to travel within a mixed traffic environment, adopting appropriate interaction strategies across different scenarios. Thus, it is important to gain a detailed understanding of the specific types of interactions that are most likely to arise. The overall purpose of t...
Article
Full-text available
To be successful, automated vehicles (AVs) need to be able to manoeuvre in mixed traffic in a way that will be accepted by road users, and maximises traffic safety and efficiency. A likely prerequisite for this success is for AVs to be able to communicate effectively with other road users in a complex traffic environment. The current study, conduct...
Preprint
Full-text available
Achieving optimal performance in human-machine systems, such as highly automated vehicles, relies, in part, on individuals' acceptance and use of the system, which is in turn affected by their enjoyment of engaging with, or experiencing, the system. This driving simulator study investigated individuals' real-time subjective evaluation of four diffe...
Preprint
Human behavior and interaction in road traffic is highly complex, with many open scientifi?c questions of high applied importance, not least in relation to recent development efforts toward automated vehicles. In parallel, recent decades have seen major advances in cognitive neuroscience models of human decision-making, but these models have mainly...
Preprint
Full-text available
This paper describes the results of a driving simulator study, which assessed the effect of different levels of HMI guidance on drivers' behaviour during transitions of control from automation. These transitions always preceded a lane-change manoeuvre, with different levels of traffic density in the offside lane. The objective of the research was t...
Technical Report
Full-text available
This Deliverable starts with a short overview of the design principles and guidelines developed for current Human Machine Interfaces (HMIs), which are predominantly developed for manually driven vehicles, or those with a number of Advanced Driver Assistance Systems (ADAS), at SAE Levels 0 and 1 (SAE, 2018). It then provides an overview of how the a...
Article
Full-text available
Using the Theory of Planned behaviour, as a theoretical framework, the current study sought to identify the salient beliefs underpinning speeding behaviour among commercial drivers in Nigeria. A sample of 13 drivers participated in one of three focus group discussions. Deductive content analysis revealed that although speeding was perceived as an a...
Article
Full-text available
Automated driving research over the past decades has mostly focused on highway environments. Recent technological developments have drawn researchers and manufacturers to look ahead at introducing automated driving in cities. The current position paper examines this challenge from the viewpoint of scientific experts. Sixteen Human Factors researche...
Preprint
Full-text available
Automated driving research over the past decades has mostly focused on highway environments. Recent technological developments have drawn researchers and manufacturers to look ahead at introducing automated driving in cities. The current position paper examines this challenge from the viewpoint of scientific experts. Sixteen Human Factors researche...
Preprint
Full-text available
In current urban traffic, pedestrians attempting to cross the road at un-signalised locations are thought to mostly use implicit communication, such as deceleration cues, to interpret a vehicle’s intention to yield. There is less reliance on explicit driver- or vehicle-based messages, such as hand/head movements, or flashing lights/beeping horns. W...
Article
Full-text available
This driving simulator study compared drivers’ eye movements during a series of lane-changes, which required different levels of motor control for their execution. Participants completed 12 lane-changing manoeuvres in three drives, categorised by degree of manual engagement with the driving task: Fully Manual Drive, Manual Intervention Required, Fu...