To understand people with ASD’s viewpoints on driving using Q-methodology (e.g., whether or not they are confident and prefer driving than other transportation).
50 with ASD (MA = 21.8 years; 82% male) 57 young adults without ASD (MA = 23.6 years; 72% male)
(i) Some young adults with ASD perceived themselves as confident and independent drivers. (ii) Some preferred to use public transportation or walk; anxiety was a barrier to driving for some. (iii) 34% with ASD had a driver licence compared to 68% of typical developing.
Diagnosis of ASD based on self-report Underrepresentation of nondrivers in the control group.
(i) To assess and compare the driving performance of drivers with and without ASD in suburban traffic environment (ii) To explore how the symptomatology of ASD hinders or facilitates the on-road driving performance
16 with ASD (MA = 25.43 years; 86% male) 21 TD (MA = 27 years; 93% male)
(i) Drivers with ASD underperformed in vehicle manoeuvring, especially at left turns, right turns (hesitant and slower), and pedestrian crossings. (ii) Drivers with ASD outperformed the TD group in rule-following aspects such as using the indicator at roundabouts and checking for cross-traffic when approaching intersections.
Being small in sample size, the participants of this study may not be representative of the broader population and can impact on the generalisability of the results. Assessor bias—not blinded to diagnosis of participants or the purpose of the study No use of independent assessor or interrater reliability checks Impact of environmental factors, such as time of day and weather conditions on driving performance, cannot be disregarded. Driving route is developed by a researcher using the route of convenience for experimentation purposes; whether it mimics traffic demands on a normal road is questionable.
An online survey to understand driving and ASD by surveying parents/caregivers of adolescents and young adults with ASD, who had driving licence or were in the process of learning to drive
parents/caregivers (mother 81%, father 13%, and caregiver 6%) The mean age of their child with ASD was 19 years, 73% male; 83% Asperger’s/high-function ASD, 9% PDD-NOS, 3% autistic disorder, and 5% others
(i) Parents were active in the teaching process (mother 81%; father 62%). (ii) 48% had a driver’s licence, 29% possessed a learner’s permit, and 70% of the parents stated that ASD affected driving ability. (iii) Particular challenges for people with ASD are complex driving demands (e.g., merging into traffic, traffic awareness, multitasking, handling unexpected changes, and sustaining attention on a long drive) (iv) Other difficulties include interpreting the actions of other drivers (e.g. reading their nonverbal social cues when in ambiguous situations).
Diagnosis of ASD is not confirmed through review of medical records Confounding impact of comorbidity is not accounted. Respondent bias (use of caregivers other than the person on the spectrum) limits validity. Use of a sample that was nonrepresentative; data collection is limited to internet survey.
An online survey using a modified version of the Driver Behaviour Questionnaire to determine whether differences exist between adult drivers with ASD and non-ASD adult drivers in terms of (i) driving history and driving behaviours, (ii) the rates of reporting violations/mistakes/driving slips as defined by DBQ, and (iii) the relative risk of such behaviours as quantified by the DBQ.
78 licenced drivers with ASD (MA = 32.9 years; 56% male, 98.7% autism/Asperger’s, and 1.3% PDD-NOS) 94 non-ASD drivers (MA = 35.5 years; 31% male)
(i) Drivers with ASD obtained their driver’s licence approximately 2 years later that non-ASD drivers. (ii) Drivers with ASD drove less days per week and had significantly lower ratings of their driving ability and a higher number of traffic violations. (iii) Drivers with ASD were also more likely to place voluntary restrictions on driving.
The pilot study relied on anonymous self-report. Participants, due to poor insight or difficulty in comparing their own driving behaviour with other drivers, may underreport their symptoms and overrate their driving ability. Report of driving behaviours through the use of standardized self-report measures would have improved the study rigor. Only the use of internet outlets for data collection may limit sample representativeness. Impact of comorbidity cannot be disregarded.
An online survey to learn about the travel patterns, needs, and barriers people with ASD encounter regarding the use of different transportation modes.
Male : female = 3 : 16
(i) Only 9.3% of the adults with ASD had a driver’s licence and many are using it as identity card rather than a licence to drive. (ii) 55.3% of the drivers with ASD () had difficulty dealing with traffic, 34% mentioned difficulty caused by distractions near roads; 27.7% mentioned difficulty judging distance, and 27.7% had difficulty with parking. (iii) Because of these difficulties, 26.1% did not drive at all.
Low representation of views of ASD adults who had a driving licence and that have driven a car regularly
An online survey to compare the characteristics of age-eligible driving and nondriving teens and explore the driving outcomes for teens with higher functioning autism spectrum disorders
(MA = 16.39 years; 83%; 24.7% autistic disorder, 14.5% PDD-NOS, 1.5% ASD, 46.4% Asperger’s, and 4.7% others)
(i) 63% of teens currently drive or plan to drive. (ii) 29% who are eligible to drive currently drive. (iii) Driving predictors included individualised education plans with driving goals, indicators of functional status, and parent experience with teaching teens to drive. (iv) 12% of teens received driving citations, and 12% of teens had been involved in a motor vehicle crash.
Respondent bias (use of caregivers other than the person on the spectrum) limits validity. Selection bias leading to nonrepresentative samples: families of teens who currently drive or plan to drive are more likely to participate in this study
Videos of 20 different driving situations with inbuilt hazards to (i) compare the ability of identifying the driving hazards by stopping the video and pointing to the hazard between people with ASD and without ASD and (ii) define whether people with ASD have difficulty in responding to hazards or orienting to them.
18 ASD males (MA = 18.79 years) 17 TD males (MA = 18.19 years)
(i) Although nonsignificant, participants with ASD showed a slower fixation on the hazard source and a slower orientation to the hazards. (ii) Greater attentional capture in the time preceding the hazards’ onset was associated with lower verbal IQ. (iii), Suggesting individuals with ASD may distribute or direct their attention differently when identifying driving hazards.
The study is limited to young male ASD adults with no specific training or driving experience. Results cannot be generalised to ASD drivers with a licence or of different age ranges or females with ASD.
To investigate how drivers with ASD respond to social and nonsocial hazards in a driving simulator compared to typically developing drivers using a driving simulator
16 ASD drivers (MA = 23.88 years; 15% male) 16 TD drivers (MA = 22.94 years; 15% male)
(i) There was no difference in reaction time to social versus nonsocial hazards for drivers with ASD. (ii) Typically developing drivers reacted more quickly to social hazards as compared to nonsocial hazards.
Small sample size and underpowered Low scores on ASD symptomatology: ASD Social Responsive Scale. Unclear of any real-life translation of the simulated driving assessment
To investigate the utility of using a driving simulator and interactive exercises (steering and pedal tasks) to address the motor aspects of predriving skills of young adults with ASD
10 ASD (MA = 15.9 years; 10 male) 31 TD (MA = 16.7 years; males = 18)
(i) Minimal performance differences were observed between the two groups in terms of the motor aspects of predriving skills. (ii) Participants with ASD needed more time (30–35 minutes) to complete the 18 interactive steering and pedal exercises. (iii) The interactive exercises and the process used worked well to address motor-related aspects of predriving skills in young adults with ASD.
Small sample size and underpowered Females are excluded in the ASD group. Unclear of any real-life translation: interactive exercises do not include any road scenes that help to eliminate the sensory overload, anxiety, and stress that participants might experience in naturalistic driving environments
To conduct an evidence-based review of intervention studies and predictor studies related to driving outcomes in teens with ADHD or ASD
intervention studies (2 RCT, 7 quasi-experiments, and 1 prospective observational study) Quasi-experimental studies: 7 on ADHD and 1 on ASD
(i) The ASD group perceives driving hazards via video clips but has difficulty in perceiving hazards if the task also requires processing of social information. (ii) The ASD group responds slower to hazard perceptions compared to controls. (iii) An instrumented vehicle, simulator training, and parent involvement invention had positive effect for speeding and hard braking for teens with ADHD. (iv) Male drivers with ADHD improved in hazard perception response times following training with hazard videos.
Heterogeneity among the studies: variability in age Inclusion criteria restricted to articles published in English and male participants Using different driving simulators, driving scenarios, outcome measures of assessment, failure to control for any prior rehabilitation, or clinical interventions lessened the methodological rigour of the studies. Grey literature is not included in the search.
Using a driving simulator to examine the demographic, clinical, and simulated driving (type and number of driving errors) differences between teens with ADHD-ASD, healthy controls (HCs).
22 ADHD-ASD (MA = 15.05 years; 17% male) 22 healthy controls (MA = 14.32 years; 59% male)
(i) Teens with ADHD-ASD performed more poorly on right eye visual acuity, selective attention, visual motor integration, cognition, and motor performance. (ii) Teens with ADHD-ASD made more errors on the driving simulator regarding visual scanning, speed regulation, lane maintenance, adjustment to stimuli, and total number of driving errors. (iii) Compared with HC teens, teens with ADHD-ASD may have more predriving skill deficits.
Sample of convenience: a Caucasian sample is not representative of the population of interest. Small sample size: underpowered study Selection bias: more concerned parents and teens with better insight enrolled in the study Berkson’s bias: test taking and driving behaviours could be influenced by the evaluator’s sitting next to the client. Hawthorne bias: the test-taking and driving behaviours are influenced by the testing site and social conditions. Did not control for medication effects on driving Simulator study: questionable of real-life driving equivalence
To examine the relationship between driving performance and executive functioning for novice drivers, with and without ASD, using a driving simulator
males 17 ASD (MA = 18.28 years) 27 healthy controls (MA = 16.59 years)
(i) ASD drivers had significantly slower reaction times during steering but not braking. (ii) ASD drivers demonstrated impaired working memory functioning, such that adding working memory demands resulted in a significant decrement in their driving performance relative to control drivers. (iii) ASD drivers demonstrated poorer overall driving ability than the control drivers.
Simulator study—questionable real-life equivalence Diagnosis based on parent report: medical records/doctors not consulted Cognitive measure is not used to assess intellectual functioning. Equivalence of comparison groups questionable: the control group was younger licenced drivers, whereas the ASD group had learner’s permits. Previous driving experience was not accounted for in both groups.
Using a virtual reality driving simulator to investigate how novice drivers with ASD differ from experienced drivers and whether virtual reality driving simulation training (VRDST) improves ASD driving performance
51 novice ASD drivers (MA = 17.96 years; 78% male) 23 in routine training (RT) 14 in standard VRDST 14 in automated VRDST 18 in eye-tracking VRDST only 333 normative licenced comparison group (MA = 40 years; 73% male)
(i) ASD drivers showed worse baseline executive function (EF) and driving skills than experienced drivers. (ii) ASD drivers performed worse than normative drivers on general tactical driving (iii) Both standard and automated VRDST significantly improved driving (e.g., better steering and speed control) and EF performance compared to RT. (iv) Eye-tracking VRDST did not significantly improve tactical performance relative to RT.
No random assignment of subjects to groups Small sample size: the study can be under powered
To illustrate the predriving skills of a teen with ADHD/ASD using a driving simulator
1 male with ASD/ADHD, 15 years old
(i) Demonstrated significant impairments related to visual motor integration and attention shift (ii) Did not perform visual scanning for traffic at cross streets and during lane changes (iii) Approached all interactions with excessive speed (iv) Poor understanding of traffic flow (v) Made gap acceptance error related to being overcautious
Single case study design: inherently faces the lack of representativeness of general population
Using a driving simulator to compare the predriving skills of a teen with ADHD/ASD to an age- and gender-matched healthy control.
1 male with ADHD/ASD, 15 years old 1 youth without ADHD/ASD, 15 years old
(i) Youth with ADHD/ASD demonstrated impairments in the ability to shift attention, perform simple sequential tasks, integrate visual-motor responses, and coordinate motor responses (ii) Youth without ADHD/ASD demonstrated intact skills in these abilities. (iii) Youth with ADHD/ASD made 44 driving error, while the youth without ADHD/ASD made 17 during the driving. (iv) Youth with ADHD/ASD had more lane maintenance, visual scanning, and speeding errors compared to the youth without ADHD/ASD.
Using a driving simulator to explore driving behaviour and visual attention in young adult drivers with high-function (HF) ASD in comparison with a community sample of nonaffected individuals matched for age and sex
10 male with HF-ASD (MA = 20.2 years) 10 matched controls (MA = 20.7 years)
(i) Youth with HF-ASD performed comparable to controls in terms of the frequency of simulated crashes and vehicle control. (ii) Youth with HF-ASD displayed a nominally higher and unvaried heart rate compared to controls. (iii) Youth with HF-ASD showed a gaze pattern suggestive of a diversion of visual attention away from high-stimulus areas of the roadway when responding to increased cognitive demands (cell phone task; continuous performance task). (iv) Youth with HF-ASD tended to position their vertical gaze higher and away from nearer objects and more toward the distance than controls.
Sample of convenience—Caucasian comparison groups are not representative of the population of interest—limits generalisability of results. Small sample size: underpowered study Without screening on age and cognitive functions, a convenient sample from the community as the control group Assessment of intellectual functioning or ASD was not obtained. Degree to which outcome measures relate to other covariates such as driving frequency and exposure is not reported.
Study one: descriptive study Study two: case control experimental design, random allocation of members to comparison groups
To assess the feasibility of outcome measures for and responsiveness of virtual reality driving package
4 teenagers with ASD—3 male and one female 2 in the performance-sensitive system (PS) group (degree of difficulty changed based on performance only) 2 in the engagement-sensitive system (ES) group (degree of difficulty changed based on performance and engagement)
(i) All participants reported that they “enjoyed the game” and noticed the changes in task difficulty. (ii) The physiological data was successfully used to assess the user’s engagement level and performance enabling the dynamic adjustment of the driving difficulty level.
Small sample size: underpowered study Equivalence of groups was questionable: effects of neither age nor driving experience are sufficiently controlled for the studies Study design does not take into account the possibility of comorbidity of ADHD in the sample group. Unclear of any real-life translation of the driving simulator study.
To generate proof of concept data to determine if EEG data is useful in ASD driving interventions
20 ASD (MA = 15.29 years; 19 males and 1 female)
(i) EEG-based group level classification models are feasible for recognizing affect and workload recognition in individuals with ASD in the context of using a desktop virtual reality driving program. (ii) Although promising, the applicability of this approach to collecting outcome data in other interventions requires further development.
Small sample size of the neurotypical comparison group Limits with interpreting EEG data of virtual reality environments as in real-life contexts
To compare the ability of identifying 10 different driving hazards by stopping the video and pointing to the hazard between people with ASD and without ASD
23 males with ASD (MA = 18.55 years; 30% ASD and 70% Asperger’s) 21 males without ASD (MA = 18.83 years)
(i) Participants with ASD identified fewer social hazards (those that involved people like pedestrians, cyclists), but not nonsocial hazards (e.g., cars). (ii) Participants with ASD were slower to respond than those without ASD.
Participants of the study are likely to have strategies prior to the experience to identify and respond to both types of hazard. Limited to only male participants Results cannot be generalised to ASD drivers with a licence or of different age ranges or females with ASD.
To investigate whether individuals with ASD have difficulty judging the location of moving objects in a driving context using a time-to-arrival task on a desktop virtual reality program
23 males with ASD (MA = 18.55 years; 7 with Autism and 16 with Asperger’s) 21 males in comparison group (MA = 18.83 years)
(i) Participants with ASD were less accurate at predicting which of the two cars in the virtual reality program would arrive first at an intersection on a straight road. (ii) There were no differences between participants with ASD and the comparison group when the simulation was along a curved road.
Participants were all nondrivers so generalisability to drivers is not possible. Unclear of any real-life translation
Videos of 20 different driving situations with inbuilt hazards to (i) compare the ability of identifying the driving hazards by stopping the video and pointing to the hazard between people with ASD and without ASD and (ii) define whether people with ASD have difficulty in responding to hazards or orienting to them.
18 ASD males (MA = 18.79 years) 17 TD males (MA = 18.19 years)
(i) Although nonsignificant, participants with ASD showed a slower fixation on the hazard source and a slower orientation to the hazards. (ii) Greater attentional capture in the time preceding the hazards onset was associated with lower verbal IQ, suggesting that individuals with ASD may distribute or direct their attention differently when identifying driving hazards.
Limited to male young adults with ASD, but with no specific training or driving experience Results cannot be generalised to ASD drivers or of different age ranges or females with ASD.
To determine if a novel virtual reality driving environment can detect between-group differences
4 males with ASD (MA = 16.87 years) 4 TD controls (MA = 15.34 years; 3 males and 1 female)
(i) The ASD group experiencing a higher number of simulated driving failures (ii) Participants with ASD had a vertically higher and horizontally right visual gaze. (iii) The ASD group had a significantly higher skin conduction level and skin conductance response rate suggesting that participants with ASD may have greater anxiety.
Small sample size: underpowered study Unclear of any real-life translation
To compare the effects on driving performance and gaze patterns using the gaze-contingent system and the gaze-insensitive, performance-based system
12 males with ASD in the gaze-contingent group (MA = 14.65 years) 6 in the performance-based group (MA = 15.93 years)
(i) The performance-based group showed a significantly higher mean vertical and right-sided gaze component when compared to the gaze-contingent group. (ii) The performance-based group showed a decrease in trial failures from pre- to post-post.
Small sample size: underpowered study. Equivalence of groups was questionable.
To determine if performance data and affective data can be combined to predict the optimum driving difficulty level of a virtual reality program
7 with ASD (age range = 13 to 17 years)
(i) Combining performance and affective state data was better at predicting the difficulty level when compared to separating the data. (ii) The number of driving performance failures and the enjoyment level had a strong relationship with the difficulty level.
Small sample size: underpowered study
Barriers to obtaining a licence and training on drivers of the spectrum ()
Questionnaires with open and closed questions to explore the facilitators or barriers in driving education experienced by individuals with ASD or ADHD who obtained a learner’s permit, from the perspective of the learner drivers and their driving instructors
14 male ADHD 19 ASD (MA = 20.7 years; 16 males and 3 females) 9 driving instructors (4 with ADHD learner drivers and 5 with ASD learner drivers)
(i) Participants with ASD required twice as many driving lessons and more on-road test than those with ADHD. (ii) Reading difficulties meant converting theory into practice was difficult. (iii) Adjusting to on-road situations that were unfamiliar of deviated from the “textbook” script was challenging. (iv) Paying attention to other road users and road signs was reported to be a problem. (v) Hazard perception and the ability to regulate the driving according to the traffic conditions were difficult for ASD participants.
Small sample size: underpowered study Use of nonvalidated outcome measures Did not consider comorbidity as a confounder Did not consider impact of prior familiarity and experience in working with people with ASD and ADHD in measuring outcomes
To systematically review the literature on factors (e.g., barriers and facilitators) affecting driving and motor vehicle transportation experiences of people with ASD
22 studies from eight databases with 2919 participants (mean age 17.3 years 364 individuals with ASD 2555 parents of youth with ASD
13 studies focused on factors affecting driving including the following: (i) Challenges in obtaining a licence (e.g., handling unexpected changes, sustaining attention for long drives, merging into traffic, and limited ability to read facial expressions and gestures) (ii) Driving confidence (not confident in reaction time, much resulted from experiences of anxiety) (iii) Driving behaviours (e.g., avoiding heavy traffic or highways, driving at night, adhering to speed regulation, and lane maintenance) (iv) Strategies to improving driving skills (e.g., direct communication, providing lessons in short intervals, starting off in quiet areas, not giving too much information or verbal correction, and address anxiety).
Research conducted on March 2015 Inclusion restricted to articles published in English Grey literature not included
To examine the problems faced by supervisors and instructors during training and the strategies that can be implemented to decrease the risks associated for drivers with Asperger’s syndrome
Four case studies on the following: (i) 20-year-old male with Asperger’s/ADHD (ii) 26-year-old male, with Asperger’s/anxiety/depression (iii) 20-year-old male with Asperger’s/ADHD/ (iv) 18-year-old male with Asperger’s/dyspraxia
(i) Problems included being easily distracted during driving, poor concentration, anxiety, and sensory overload (ii) Strategies included are as follows: (a) Communication book for parents/learners/instructors to reinforce the sequence of tasks using a consistent approach are provided. (b) Regular lessons were conducted. (c) The use of keywords and structured language in instructions for consistency reduced confusion and anxiety. (d) Reduce discussions on topic of interest to increase focus on the driving task. (e) Break tasks down and working through smaller components in sequence to reduce anxiety. (f) Instructors used “what if” scenarios to broaden participant’s understanding of unpredictable drivers and pedestrians. (g) Instructors used visual markers for judgement of distance, crash avoidance space, and indicator distance rules.
Interpretation of results of the study dependent on the sensitivity and integrity of the investigator Case study design: inherently faces the lack of representativeness of general population Efforts undertaken to ensure trustworthiness, credibility, transferability, dependability, confirmability, and rigour of the study were not reported.
Study included the collection of both driving and public transport data, with sufficient data about driving to be included in this review.
