Driver Attention in Automatic Transmission Cars
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Regenerative and Technological Section / Original Paper
Gerontology 2012;58:181–187 DOI: 10.1159/000329769
Does Automatic Transmission Improve Driving Behavior in Older Drivers?
Helena Selander a, b Ingrid Bolin b Torbjörn Falkmer a, c–e
a School of Health Sciences, Jönköping University, Jönköping , b Mobilitetscenter, Gothenburg , and c Rehabilitation Medicine, Faculty of Health Sciences, Linköping University, Linköping , Sweden; d School of Occupational Therapy and Social Work, Curtin University, Perth, W.A. , and e School of Occupational Therapy, La Trobe University, Melbourne, Vic. , Australia
proved the older participants’ driving behavior as demon- strated by safer speed adjustment in urban areas, greater maneuvering skills, safer lane position and driving in accor- dance with the speed regulations. Conclusion: Switching to automatic transmission may be recommended for older drivers as a means to maintain safe driving and thereby the quality of their transport mobility.
Copyright © 2011 S. Karger AG, Basel
In developed countries, driving is seen as an impor- tant symbol of identity and independence [1] . The car en- ables mobility and access to essential services and social activities [2–4] . Consequently, most older drivers contin- ue to drive as they age [5] . However, the complex interac- tion between sensory, cognitive and perceptual-motor processes required for safe driving are vulnerable due to the inherent changes that come with age [6] .
Furthermore, as traffic density increases, the complex- ity of the driving task will increase [7] . Driving in complex traffic environments leads to high workload, especially in traffic situations that require interaction with other road users, for example at T-junctions [8] . In these interactive situations, older drivers have fewer cognitive processing
Key Words
Automatic transmission � Manual transmission � Mobility � Older drivers � Speed adjustment � Traffic safety
Abstract
Background: Most older drivers continue to drive as they age. To maintain safe and independent transport, mobility is important for all individuals, but especially for older drivers. Objective: The objective of this study was to investigate whether automatic transmission, compared with manual transmission, may improve the driving behavior of older drivers. Method: In total, 31 older drivers (mean age 75.2 years) and 32 younger drivers – used as a control group (mean age 39.2 years) – were assessed twice on the same fixed route; once in a car with manual transmission and once in a car with automatic transmission. The cars were other- wise identical. The driving behavior was assessed with the Ryd On-Road Assessment driving protocol. Time to comple- tion of left turns (right-hand side driving) and the impact of a distraction task were measured. Results: The older group had more driving errors than the younger group, in both the manual and the automatic transmission car. However, and contrary to the younger drivers, automatic transmission im-
Received: February 2, 2011 Accepted: May 31, 2011 Published online: August 25, 2011
Prof. Torbjörn Falkmer, PhD School of Occupational Therapy and Social Work Curtin University, GPO BOX U1987 Perth, WA 6845 (Australia) Tel. +61 8 9266 9051, E-Mail T.Falkmer @ curtin.edu.au
© 2011 S. Karger AG, Basel 0304–324X/12/0582–0181$38.00/0
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resources than younger drivers [8] . In fact, older drivers crash more frequently in complex traffic environments, e.g. in intersections that involve turning, especially turn- ing across the oncoming lane, and in complex traffic situ- ations, e.g. when overtaking and merging [9–11] .
The Michon model of driving behavior comprises a hierarchy of three levels [12] . The strategic level involves planning, timing and route, usually made before the ac- tual driving. The tactical level involves activities and de- cisions while driving, e.g. adjusting speed and judgment of traffic situations. The operational level is the most basic and involves the actual perceptual-motor skills to control the vehicle, e.g. steering, braking and gear changing. There have been contradictory results about older driv- ers’ performance regarding tactical and operational driv- ing skills. While some claim younger drivers make more driving errors than their older counterparts [13] , older drivers have been found to have more problems with op- erational driving skills, i.e. they drive more slowly and with poor lane positioning [14] . Another operational driving skill, gear changing, is often seen as an automa- tized task [12, 15] . For a novice driver, gear changing can be difficult and will not be automatized until it is over- learned after increasing practice [16] . However, for older drivers the execution of motor skills can become less au- tomatized than previously [17] , which could affect gear changing. In a previous study, inappropriate gear chang- es were found to be the fourth most common driving er- ror in older drivers [18] .
If older drivers fulfill the medical requirements for driving, the goal should be to maintain their transport mobility by driving safely for as long as possible [2–4] . Educational and training programs are available for old- er drivers to accomplish this. However, little is known about how other strategies can improve their driving be- havior. For example, it remains unknown how transmis- sion type affects driving behavior and whether or not a car with automatic transmission enhances safe driving. However, in a simulator study it was found that adoles- cent males with attention deficit/hyperactive disorders benefitted from using manual compared with automatic transmission regarding their attention skills [19] . In an- other simulator study, the components of braking time were analyzed, in order to assess the effects of, e.g. age and vehicle transmission type on braking time’s two pri- mary components, perception-reaction time and brake- movement time [20] . Whereas transmission type did not significantly affect either perception-reaction time or brake-movement time, perception-reaction time in- creased from 0.35 to 0.43 s with age. However, brake-
movement time did not change with age. All these find- ings were based on low/median cost simulator driving, where the transmission type may be difficult to simulate [21–23] . In another study, physiological activity of drivers aged 25–35 years was measured, where it was found that use of automatic transmission may reduce stress reac- tions when driving in heavy city traffic [24] . To date, no studies comparing driving behavior in older drivers when driving manual versus automatic transmission cars have been published. Consequently, the aim of the present study was to investigate whether a car with automatic, compared with manual, transmission improves driving behavior in older drivers.
Methods
In order to achieve the objective of this study, a younger group of drivers was used as a control group. The study was approved by a local ethics committee in Gothenburg, Sweden. The data were collected in a driving assessment unit in Sweden from 2008–2009.
Participants The participants were recruited via the Vehicle Registration
Office, local senior organizations and local businesses. Invita- tion letters were sent to potential participants explaining the purpose of the study. In total, 63 drivers agreed to participate in the study. The two groups were the older driver group (n = 31, 42% women) and the younger driver group (n = 32, 44% wom- en). The older group’s mean age was 75.2 (SD = 4.9, ranging from 70 to 90 years) and the younger group’s mean age was 39.2 (SD = 5.2, ranging from 27 to 48 years). The younger group did not comprise any novice drivers. All older participants current- ly owned and drove manual transmission cars. Twenty-eight participants in the younger group owned and drove manual transmission cars, while four participants owned automatic transmission cars. All participants had a valid driving license for manual transmission.
Procedures The participants were assessed twice on the same fixed route;
once in a car with manual transmission and once in a car with automatic transmission, in a randomly allocated balanced order. Every second participant in both groups started with the manual transmission car and continued immediately after with the au- tomatic transmission car. The cars were identical except for the transmission type, i.e. the same car make (Volvo V50) and model year. Both cars were equipped with dual controls. Each driving test took approximately 35 min on public roads in a suburban dis- trict in right-hand side traffic. The route comprised a diversity of intersections, right and left turns, roundabouts and road signs. A driving assessor (a specially trained occupational therapist) as- sessed the drivers’ behavior, e.g. how they followed instructions, maneuvered, managed lane positioning, obeyed traffic rules, in- teracted with other road users, and their attention. Their behavior was noted on a Ryd On-Road Assessment (ROA) driving protocol
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scoring sheet, further presented below. A driving instructor had the safety responsibility (dual controls) and gave directions to fol- low throughout the route. The driving instructor sat in the front passenger seat and the driving assessor in the back seat to the right. A secondary task, aiming to distract the drivers, was given at pre-defined spots along the route. In addition to the assessment of their driving behaviors, their performance on this secondary task and the time it took to complete predefined left turns were measured. Details on these two measurements are further pre- sented below. After the two driving tests, each participant com- pleted a questionnaire about their experience of the differences between the two cars.
Driving Assessment Measurements ROA Protocol ROA was developed for a previous study and is utilized clini-
cally at the driving assessment unit where the tests took place [18] . The scoring sheet comprises 34 specified items in seven catego-
ries, i.e. speed, position, attention, indicator, maneuvering, in- structions, and traffic rules, as shown in figure 1 . Errors made are graded on a 0–2 scale, where 0 implies normal driving behavior, 1 indicates minor error, while 2 indicates considerable risk-taking behavior. There is no upper limit to the scores.
Secondary Task A secondary distraction task was predetermined at four
roundabouts in each driving test. The participants received infor- mation about the nature of this secondary distraction task prior to the driving test. The instructions were to count out loud, start- ing from a specific number, e.g. 345, minus 3, as many times as possible during the roundabout. The distraction task had to be auditory, since we did not want to visually distract the drivers. This auditory method is a classic distraction task, built into valid and reliable test such as the TSST [25] among others. The number of correct numerical operations (x) was noted, as was the time per correct calculation (y). At the same time, a score based on the
1. Speed 2. Position 3. Attention 4. Indicator 5. Maneuvering 6. Instructions 7. Traffic rules
Too fast for the situation
To the right To the right No use of indicator
Handling pedals Repeating needed
Give right of way
Too slow for the situation
To the left To the left Wrong direction
Steering Reminding needed
Yield to traffic
Slow/late braking Close to the vehicle in front
Ahead Too late Changing gear Driving the wrong way
Obligation to stop
Braking without reason
Swaying between lanes
To the rear, including rear view mirror
Too early Managing controls to the left
Exceeding speed limit
Blind spot, to the right
Does not switch it off
Managing controls to the right
Rules regarding buses
Blind spot, to the left
Reversing Crossing a solid lane line
Fig. 1. The ROA protocol. Items indicated in italics were the ones in which the automatic transmission car had a significantly positive impact on the older group, which is further displayed in the bar chart in the lower part of the figure. Error bars display the positive SE of the mean.
0 1 2 3 4
Average number of errors
Too fast for the situation
5 6 7 8
To the left
Handling pedals
Change gear
Exceeding speed limit
Automatic Manual
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number of driving errors in the roundabout (z), using a 1–5 scale where higher was better, was noted. The scoring of (z) was done according to the following five score criteria: 5 = no errors; 4 = 1 error/need repeated instructions; 3 = 2 errors; 2 = 3 errors; 1 = 4 or more errors.
The outcome algorithm was:
2 .
x z
y �
The secondary task was thus both a distraction task and an out- come measurement.
Intersections – Left Turns At three intersections, the instruction was to turn left after a
complete stop from a feeder road into a trunk road with priority. From the driving instructor’s word of command when free access was given to the trunk road, the drivers started to drive and the time (in seconds) was measured to a specific point (mean 68 m) on the trunk road.
Questionnaire The questionnaire comprised 13 questions about the partici-
pant’s experience and attitudes towards automatic transmission cars, e.g. ‘If you were to buy a new car, what sort of transmission would you prefer?’
Statistical Analyses Statistical analyses were performed using SPSS � (version 17.0).
All variables were tested for normal distribution with the use of the Kolmogorov-Smirnov test. � 2 tests, Wilcoxon signed-rank tests, Mann-Whitney U tests, and paired samples and indepen- dent samples Student’s t tests were used with the � -level set at 0.05. Cohen’s d was calculated where applicable.
Results
As shown in table 1 , the older group demonstrated more driving errors, both in the car with manual trans- mission and in the automatic transmission car compared with the younger group, (Cohen’s d = 0.94). The younger group performed the left turns in shorter time than the older group in the manual transmission car (Cohen’s d = 0.78), as well as in the automatic transmission car (Co- hen’s d = 0.54). During the secondary task, the younger group performed slightly better (Cohen’s d = 0.19) in the manual transmission car, whereas no differences were found between the two groups in the automatic transmis- sion car.
In the older group, driving the automatic transmission car improved their driving behavior regarding the num- ber of driving errors and during the turning left task (Co- hen’s d = 0.60), compared with when they drove the man- ual transmission car. However, the car with automatic transmission did not affect the driving behavior of the younger group, except for the turning left task (Cohen’s d = 0.67).
Driving the exact same route twice implies that pos- sible learning may have occurred for the drivers. In order to check for such effects, results from the first drive were compared with results from the second, as shown in ta- ble 1 . Driving errors were found to be less frequent in younger drivers the second time they drove, regardless of transmission type. Furthermore, both groups of drivers managed the secondary task better the second time they
Table 1. Driving measurements for the manual and automatic transmission car conditions, and for the older and the younger group, in addition to their 1st and 2nd drives, respectively
O lder group (n = 31) Within-group tests and p values
Younger group (n = 32) Within-group tests and p values
Between-groups test and p values
mean 95% CI mean 95% CI
Driving errors (manual) 24.3 19.0–29.7 z = 4.86, p < 0.001*
6.2 4.8–7.5 z = 1.24, p = 0.21
z = 5.65, p < 0.001* Driving errors (automatic) 10.6 8.1–13.1 5.4 3.9–6.9 t = 3.63, p = 0.001* Driving errors (1st drive) 15.5 11.7–19.3
z = 1.10, p = 0.27 6.5 5.3–7.7
z = 2.49, p = 0.013* z = 4.46, p < 0.001*
Driving errors (2nd drive) 19.4 13.7–25.1 5.1 3.5–6.7 z = 4.28, p < 0.001* Left turns (manual), s 12.8 12.3–13.4
t = 3.17, p = 0.003* 11.9 11.5–12.2
t = 3.78, p = 0.001* t = 3.03, p = 0.004*
Left turns (automatic), s 11.9 11.5–12.2 11.4 11.0–11.7 t = 2.14, p = 0.036* Left turns (1st drive), s 12.5 12.2–12.8
t = 0.88, p = 0.38 11.7 11.3–12.0
t = 0.88, p = 0.39 t = 3.68, p = 0.001*
Left turns (2nd drive), s 12.2 11.5–12.8 11.5 11.2–11.9 t = 1.81, p = 0.075 Secondary task (manual) 4.1 3.5–4.8
t = 1.31, p = 0.20 4.5 3.7–5.3
t = 0.02, p = 0.98 t = 0.74, p = 0.046*
Secondary task (automatic) 4.6 3.5–4.9 4.5 3.8–5.2 t = 0.08, p = 0.94 Secondary task (1st drive) 3.8 3.1–4.5
t = 3.80, p = 0.001* 4.2 3.5–4.9
t = 6.19, p < 0.001* t = 0.87, p = 0.39
Secondary task (2nd drive) 4.9 4.2–5.6 5.0 4.2–5.8 t = 0.31, p = 0.76 As terisk indicates significant difference.
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drove the route, regardless of type of transmission (Co- hen’s d = 0.68 for the older group and 1.10 for the young- er group). As further shown in table 1 , the younger group performed left turns quicker than the older group (Co- hen’s d = 0.93), but only in the first drive, regardless of transmission type.
The automatic transmission car had a positive impact on the driving behavior of the older group in five driving items within the ROA protocol. The two showing the largest impacts were Maneuvering – Change gear (z = 4.63, p ! 0.001), indicating inappropriate gear usage, and Speed – Too fast for the situation (z = 3.51, p ! 0.001), re- lating to problems with controlling the speed according to the situation. The other three items were Maneu- vering – Handling pedals (z = 2.83, p = 0.005), Traffic rules – Exceeding speed limit (z = 2.59, p = 0.010), and Position – To the left (z = 2.22, p = 0.027).
When asked what type of transmission they would choose if they were to buy a new car, more than half of the older participants (58%) stated that they would buy a car with automatic transmission ( � 2 = 9.7, p = 0.008). Thir- teen percent would choose manual transmission and an- other 29% stated type of transmission was of less impor- tance when buying a car. For the younger participants, 53% would choose automatic transmission, 19% manual transmission and another 28% stated the type was of less importance for them ( � 2 = 6.1, p = 0.050).
Discussion
The present study found that the older participants’ driving behavior improved when driving a car with auto- matic transmission. As a result of the automatic trans- mission, they displayed safer speed adjustments in urban areas, safer lane positioning, greater maneuvering skills and better attention to the speed regulations. Further- more, their left turns improved by driving a car with au- tomatic transmission. These results are consistent with other results, suggesting that manual gear changing is not an entirely automatized process [16] , but in contrast to other findings [26] . Contrary to our findings in the older group, automatic transmission had only a minor effect on the driving behavior of the younger group. As a matter of fact, the only effect of automatic transmission was on their left turns.
The present study measured driving errors as an out- come variable. Driving errors are defined as ‘…unwanted results of involuntary actions whereas violations are conscious deviation from a rule or safe practice’ [27] . Driv-
ing errors are thought to diminish with experience [28] . However, experienced drivers may actually display driv- ing behaviors that can be dangerous [29] . Improved driv- ing skills do not always indicate error-free driving behav- ior. Instead, there are different types of errors, with dif- ferent kinds of implications [30] . Some driving errors do not disappear with experience and age. They may, actu- ally, have become a habitual part of the driving behavior over many years for some older drivers [31] . In the present study, certain driving errors were more common than others in the older drivers group, e.g. speed adjustment and positioning, and these errors do predict crashes in older drivers [32, 33] . Furthermore, and similar to our findings, Reason et al. [31] found frequent driving errors regarding gear changing.
Several studies have reported that older drivers self- regulate their driving in certain driving situations, for example by driving slower or by reducing the time and distance driven [3, 5] . Moreover, older drivers seem to compensate for distractions by driving slower in complex traffic environments [34] . As shown in figure 1 , a fre- quent driving error identified in the present study was that the older drivers drove faster than appropriate for the traffic situation. They might not have exceeded the speed limits, but their speed was deemed too high for the ac- tual situation, e.g. when meeting vulnerable road users, crossing an intersection or driving through roundabouts. Driving requires simultaneous use of central and periph- eral vision [35] . To determine speed, the main cue is the peripheral vision [28] , which is important for safe driving [36] . Deterioration in visual functions may be a risk factor for crashes in older adults [36] . The inherent deteriora- tion of the peripheral vision in humans while aging may actually be an explanation for our results. Correlations between decreased vision and speeding errors found in previous research support this suggestion [37] .
The present study included a secondary task as a dis- traction. The term (driver) distraction is regularly used to refer to inattention or attending to something irrele- vant. A definition of driver distraction is: ‘…when a driver is delayed in the recognition of information need- ed to safely accomplish the driving task because some event, activity, object, or person within or outside the vehicle compelled or tended to induce the driver’s shift- ing attention away from the driving task’ [38] . Many studies have focused on driver distraction, in particular on in-vehicle sources like mobile phones [34, 39] . Man- ual gear changing appeared to distract the older drivers in the present study. There was a significant difference between the older and the younger group on the second-
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ary task, when driving the car with manual transmis- sion. Similar age-related distraction effects have been found for both mobile phone usage and for radio tuning [40] .
As an age group, our younger group was, in fact, ‘mid- dle aged’. This group constitutes the safest age cohorts of drivers [28] . Thus, it comes as no surprise that the auto- matic transmission car had no major effect on their driv- ing behavior. Compared with the older drivers, they had fewer driving errors with both the manual transmission car and the automatic transmission car. Apparently, pos- sible distraction from manual gear shifting was small enough not to be detected by the driver behavior mea- surements this study utilized.
A limitation of this study was the relatively small sam- ple size. Moreover, there was no measurement of intra- rater, interrater or test-retest reliability of the ROA proto- col. In addition, the secondary task outcome algorithm, specifically designed for the present study, was based on the following two assumptions: (a) the ability to perform a correct calculation was weighted as more important than the time it took, and (b) the number of errors on the primary task (driving) had a larger impact on the out- come than both the number of correct answers (second- ary task) and time per correct calculation (secondary task). However, this algorithm has not been used in previ- ous studies and not been assessed from a content validity aspect. Considering the fact that the algorithm was used
within all four conditions, viz. younger group manual transmission, younger group automatic transmission, older group manual transmission and older group auto- matic transmission, any measurement error due to the algorithm would most likely have affected all four condi- tions similarly. Furthermore, there was a risk that biased scoring may have occurred, since the assessor – for obvi- ous reasons – could not be blinded to the participants’ group belonging.
Conclusions
Automatic transmission improved the older partici- pants’ driving behavior by safer speed adjustments in ur- ban areas, greater maneuvering skills, safer lane position- ing and driving according to the existing speed limits. However, for younger drivers, automatic transmission had less effect on their driving behavior. Switching to au- tomatic transmission may be recommended for older drivers as a means to maintain safe driving and thereby the quality of their transport mobility.
Acknowledgements
Our sincere thanks are expressed to those who participated in the study and to Assoc. Prof. Angus Buchanan. This study was funded by the Swedish Transport Administration.
References
1 Whitehead BJ, Howie L, Lovell RK: Older people’s experience of driver licence cancel- lation: a phenomenological study. Austral Occup Ther J 2006; 53: 173–180.
2 Marottoli RA, de Leon CFM, Glass TA, Wil- liams CS, Cooney LM Jr, Berkman LF: Con- sequences of driving cessation: decreased out-of-home activity levels. J Gerontol B Psy- chol Sci Soc Sci 2000; 55:S334–S340.
3 Owsley C: Driving mobility, older adults and quality of life. Gerontechnology 2002; 1: 220– 230.
4 Oxley J, Whelan M: It cannot be all about safety: the benefits of prolonged mobility. Traffic Inj Prev 2008; 9: 367–378.
5 Unsworth CA, Wells Y, Browning C, Thom- as SA, Kendig H: To continue, modify or re- linquish driving: findings from a longitu- dinal study of healthy ageing. Gerontology 2007; 53: 423–431.
6 Ball KK, Wadley VG, Edwards JD: Advances in technology used to assess and retrain old- er drivers. Gerontechnology 2002; 1: 251–261.
7 de Waard D: The Measurement of Driver’s Mental Workload: The Traffic Research Centre. Haren, University of Groningen, 1996.
8 Verwey WB: On-line driver workload esti- mation. Effects of road situation and age on secondary task measures. Ergonomics 2000; 43: 187–209.
9 Clarke DD, Forsyth R, Wright R: Behav- ioural factors in accidents at road junctions: the use of a genetic algorithm to extract de- scriptive rules from police case files. Accid Anal Prev 1998; 30: 223–234.
10 McGwin G Jr, Brown DB: Characteristics of traffic crashes among young, middle-aged, and older drivers. Accid Anal Prev 1999; 31: 181–198.
11 Mayhew DR, Simpson HM, Ferguson SA: Collisions involving senior drivers: high-risk conditions and locations. Traffic Inj Prev 2006; 7: 117–124.
12 Michon JA: A Critical View of Driver Behav- iour Models: What Do We Know, What Should We Do? New York, Plenum Press, 1985.
13 Carr D, Jackson TW, Madden DJ, Cohen HJ: The effect of age on driving skills. J Am Geri- atr Soc 1992; 40: 567–573.
14 Perryman KM, Fitten LJ: Effects of normal aging on the performance of motor-vehicle operational skills. J Geriatr Psychiatry Neu- rol 1996; 9: 136–141.
15 Baddeley A: Working Memory: An Over- view; Working Memory and Education. London, Elsevier, 2006.
16 Shinar D, Meir M, Ben-Shoham I: How auto- matic is manual gear shifting? Hum Factors 1998; 40: 647–654.
17 Brouwer WH, Ponds RWHM: Driving com- petence in older persons. Disabil Rehabil 1994; 16: 149–161.
18 Selander H, Lee HC, Johansson K, Falkmer T: Older drivers: on-road and off-road re- sults. Accid Anal Prev 2011; 43: 1348–1354.
Older Drivers and Automatic Transmission
Gerontology 2012;58:181–187 187
19 Cox DJ, Punja M, Powers K, Merkel RL, Bur- ket R, Moore M, Thorndike F, Kovatchev B: Manual transmission enhances attention and driving performance of ADHD adoles- cent males: pilot study. J Atten Disord 2006; 10: 212–216.
20 Warshawsky-Livne L, Shinar D: Effects of uncertainty, transmission type, driver age and gender on brake reaction and movement time. J Safe Res 2002; 33: 117–128.
21 Falkmer T: The trainer project – develop- ment of a new cost-effective Pan-European driver training methodology and how to evaluate it: SIMSEM 2002. Copenhagen, SIMSEM, 2002.
22 Falkmer T: Truck and bus driver training, can simulation contribute?; in Dorn L (ed): Driver Behaviour and Training. Aldershot, Ashgate Publishing, 2005, vol 2, pp 93–104.
23 Falkmer T, Gregersen NP: The trainer proj- ect – the evaluation of a new simulator-based driver training methodology; in Dorn L (ed): Driver Behaviour and Training. Aldershot, Ashgate Publishing, 2003, pp 407.
24 Zeier H: Concurrent physiological activity of driver and passenger when driving with and without automatic transmission in heavy city traffic. Ergonomics 1979; 22: 799–810.
25 Kirschbaum C, Pirke K, Hellhammer D: The ‘trier social stress test’ – a tool for investi- gating psychobiological stress responses in a laboratory setting. Neuropsychobiology 1993; 28: 76–81.
26 Ranney TA: Models of driving behavior: a review of their evolution. Accid Anal Prev 1994; 26: 733–750.
27 Ozkan T, Lajunen T, Chliaoutakis JE, Parker D, Summala H: Cross-cultural differences in driving skills: a comparison of six countries. Accid Anal Prev 2006; 38: 1011–1018.
28 Evans L: Traffic Safety, ed 1. Bloomfield Hills, Science Serving Society, 2004.
29 Summala H: Automatization, automation, and modeling of driver’s behavior. Recher- che Transports Sécurité 2000; 66: 35–45.
30 Stanton NA, Salmon PM: Human error tax- onomies applied to driving: a generic driver error taxonomy and its implications for in- telligent transport systems. Safe Sci 2009; 47: 227–237.
31 Reason J, Manstead A, Stradling S, Baxter J, Campbell K: Errors and violations on the roads: a real distinction? Ergonomics 1990; 33: 1315–1332.
32 Classen S, Shechtman O, Awadzi KD, Joo Y, Lanford DN: Traffic violations versus driv- ing errors of older adults: informing clinical practice. Am J Occup Ther 2010; 64: 233–241.
33 Braitman KA, Kirley BB, Ferguson S, Chaud- hary NK: Factors leading to older drivers’ in- tersection crashes. Traffic Inj Prev 2007; 8: 267–274.
34 Horberry T, Anderson J, Regan MA, Triggs TJ, Brown J: Driver distraction: the effects of concurrent in-vehicle tasks, road environ- ment complexity and age on driving perfor- mance. Accid Anal Prev 2006; 38: 185–191.
35 Owsley C, McGwin G Jr: Vision and driving. Vision Res 2010; 50: 2348–2361.
36 Owsley C, McGwin G Jr: Vision impairment and driving. Surv Ophthalmol 1999; 43: 535– 550.
37 Baldock MRJ, Berndt A, Mathias JL: The functional correlates of older drivers’ on- road driving test errors. Topics Ger Rehab 2008; 24: 204–223.
38 Treat JR: A study of pre-crash factors in- volved in traffic accidents. Ann Arbor, Uni- versity of Michigan, Highway Safety Re- search Institute, 1980.
39 Ma R, Kaber DB: Situation awareness and workload in driving while using adaptive cruise control and a cell phone. Int J Ind Er- gon 2005; 35: 939–953.
40 McKnight AJ, McKnight AS: The effect of cellular phone use upon driver attention. Ac- cid Anal Prev 1993; 25: 259–265.
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