lable at ScienceDirect

Applied Ergonomics 42 (2011) 529–532

Contents lists avai

Applied Ergonomics

journal homepage: www.elsevier .com/locate/apergo

Editorial

Planes, trains and automobiles: Contemporary ergonomics researchin transportation safety

1. Introduction to transport safety

Despite the best efforts of researchers, politicians, policy-makers and transport designers and engineers, the levels of nearmisses, accidents and fatalities across all transportation modesremain at an unacceptably high level. For example, within roadtransport, every year over a million people are known to die onthe world’s roads (World Health Organisation, 2004). Within avia-tion, the Aircraft Crashes Record Office (ACRO) reported a total of127 passenger aircraft accidents during 2009 which led to 1104deaths (ACRO, 2010). Unsurprisingly then, transportation safetyacross all modes remains a prominent focus within ergonomicsresearch efforts. The topic of transport is a regular feature inApplied Ergonomics, featuring over forty papers in the last threeyears, with papers on road vehicles (Horberry and Inwood, 2010;Isler and Starkey, 2010; Walker et al., 2009), aviation (Chang andYeh, 2010; Caser, 2009; Roach et al., 2011; Stanton et al., 2009)and rail (Dorrian et al., 2011; Ryan et al., 2009). A recent specialissue of Applied Ergonomics considered driver modelling in auto-motive systems (Cacciabue et al., 2010). The subject matter is alsowithin the scope of the International Ergonomics Association’stechnical committees (Caple, 2010). The purpose of this specialissue is to draw attention to some of the latest research trends intransportation safety and ergonomics. We are pleased to presenta range of papers encompassing a range of transportation modes,incorporating real world case studies, simulator-based experimen-tation, methodology development, and review papers. Thesepapers cover the design of safety-related systems both inside thevehicle and in the environment, evaluation of in-vehicle informa-tion systems, and research into the sources and effects of driverdistraction. These three themes are used to structure the editorialand special issue. At the end of the editorial, some simple take-home messages are presented.

2. Safety-related systems

The design of safely-related systems represents a key challengeacross the transportation modes. In this special issue, four papersare concerned with the design of safety-related systems in roadand rail transportation: Young et al. (Safe driving in a greenworld),Uchida et al. (Countermeasures to prevent detection failure onvehicles approaching on collision course), Lenné et al. (Driverbehaviour at rail level crossings) and Johanning (vibration and

0003-6870/$ – see front matter � 2010 Elsevier Ltd and The Ergonomics Society. All rigdoi:10.1016/j.apergo.2010.11.003

shock exposure of maintenance-of-way vehicles in the railroadindustry).

In the context of the currently highly popular concept of ‘eco’ or‘green’-driving, Young et al. argue that the twin goals of safe andfuel-efficient driving may, at times, seem to be conflicting. This isnot always the case however, as both excessive speed and aggres-sive driving have been implicated in fatal accidents and poor fueleconomy. Young et al. identify the five main features of greendriving as: planning ahead to avoid stopping if possible, usingmoderate engine speeds, changing up a gear as soon as practicallypossible, avoiding heavy braking and using engine braking forsmooth deceleration. It is highly likely that driving using thesefive principles would also constitute many of the elements of safervehicle control, particularly when planning ahead is involved. AsYoung et al. point out, the adoption of a system of vehicle control(such as that advocated by the Institute of Advanced Motorists orthe Royal Society for the Prevention of Accidents) can make drivingboth safer and more fuel-efficient. They also argue that the provi-sion of any additional in-vehicle information system to promotesafer and more fuel-efficient driving should avoid distracting thedriver from their main sources of visual information outside thevehicle. Young et al. consider a range of potential IVIS devices(such as satellite navigation, congestion assistant, intelligent speedadaptation, and so on) and their role in safer and greener driving.They conclude that these devices will be competing for the driver’slimited attentional resources, and therefore any implementationneeds to be undertakenwith careful design and evaluation to avoiddriver distraction (Regan et al., 2008).

Crashes at intersections currently represent a significantproblem in road transport (e.g. Mori et al., 2008; Sandin, 2009;Gstalter and Fastenmeier, 2010). Uchida et al. argue that collisionsbetween vehicles crossing the paths of others at intersectionswithout signals are a common cause of such crashes. When theseaccidents happen, they tend to have a high rate of fatalities. Theseaccidents seem to result from a quirk of perception (at certainangles of approach another vehicle in the driver’s peripheral visionappears not to be detected, as there is no relative change in move-ment), that means that the driver is unaware of the other vehicle ona collision course, even though it is within their field of view.Uchida et al. investigated the ability of drivers to detect othervehicle on a collision course in the safety of a driving simulator.They found that non-detection occurred when the vehicle on thecollision course was on an offset approach angle of sixty degrees.This offset approach anglewasn’t due to the vehicle being obscured,

hts reserved.

Editorial / Applied Ergonomics 42 (2011) 529–532530

Uchida et al. also ran a trial with the approach obscured and theeffect was removed. In another trial, they found that the presenceof a directive auditory warning can help the driver detect anothervehicle on a collision course, as can an active scanning strategy(i.e., searching across the orthogonal carriageway). Taken together,all three strategies offer a systems approach to countermeasures(i.e., environment, training and in-car system) aimed at reducingthe likelihood of collisions at intersections without signals.

Lenné et al. report that despite the general improvements in railsafety, there is still poor compliance with level crossings controls.The two main causes being driver error (they do not appreciatethe significance of the information if they are aware of it at all)and violation (the driver deliberately ignores the informationdespite being fully aware of it). Although countermeasures havebeen variously implemented in an attempt to gain compliance,they tend not to be formally evaluated, and so few conclusionscan be drawn about the success of different approaches. Lennéet al. therefore set out to investigate the effects that passive controls(e.g., Stop signs) and active controls (e.g., flashing red signals andtraffic lights) had on driver compliance, using a driving simulator.The results from the study showed that drivers were more likelyto comply with red flashing lights than traffic signals or the stopsign. The addition of an additional warning sign in advance of thelevel crossing (when the level crossingwas not visible by the driver)led to lower approach speeds. Lenné et al. argue for a combination ofinterventions, comprising advanced warning of the level crossing(passive control), together with information about the presence ofany oncoming train (active control) and flashing red lights (activecontrol) as this is most likely to gain greatest compliance.

Despite the fact that prolonged intense whole-body vibrationexposure has previously been identified as a key contributory factorto accelerated degenerative spinal diseases, back pain and prolapseddiscs, Johanning argues that there is currently only limited informa-tion regarding the health and safety risk ofwhole-body vibration andshock exposure among railroad maintenance vehicle operators.Johanning measured the vibration and shock of seven different rail-road maintenance vehicles and compared them to current Interna-tional standards and professional guidelines. Further, a spinal injuryprediction method, the VibRisk model, was compared with thecurrent ISO 2631-5 risk prediction. In conclusion, Johanning foundthat five of the seven maintenance vehicles tested exceeded thecurrent whole-body vibration exposure guideline for 8 h exposureduration in the vertical axis. With regard to the two spinal injuryprediction models, inconsistencies were found when calculatingrisk for parts of the lumbar spine, with the VibRisk model suggestingdifferent and higher risk of vertebral endplate failure for individuallumbar levels and the ISO 2631-5 model suggesting lower risk levelsand being unable to differentiate between different disk levels anddriver posture. Work modifications and more adequate suspensionseats are recommended as ways in which to prevent harmful expo-sure to vibration and shock when operating maintenance vehicles.In closing, Johanning recommends further investigation in thisarea, particularly with regard to different maintenance vehicles andalso the long term occupational health risk associated with repeatedshocks and jolts.

3. Evaluation of in-vehicle information systems

Evaluating in-vehicle information systems in terms of theirusability and effects ondriver performanceand safety is a keycompo-nent of in-vehicle systemdesign. Four papers in the special issue dealwith the evaluation of in-vehicle information systems: Harvey et al.(A usability evaluation toolkit for in-vehicle information systems),Bronstrom et al. (Correlation between safety assessments in thedriver-car-interaction design process), Mitsopoulos-Rubens et al.

(Effects on driving performance of interacting with an in-vehiclemusic player), and Stanton et al. (Detection of new in-path targetsby drivers using Stop & Go Adaptive Cruise Control).

Harvey et al. caution that usability evaluation of in-vehiclesystems must be designed specifically for the context of use for thespecific system being assessed. This suggests that many off-the-shelfevaluation heuristics might be underperforming. Contextual speci-ficity includes defining the task–user–system interactions, thescenarios in which the device(s) will be used and the criteria forwhich usability will be evaluated. This planning is further compli-cated by the fact that there is little universal agreement over the defi-nition of usability. Harvey et al. identify six common themes tousability however, comprising: safety, varying environmental condi-tions, range of users, training provision, varying frequency of use anduptake. Based on the contextual analysis and the principles for select-ing evaluation methods (i.e., information requirements, stage ofdevelopment, resources available and people involved), Harveyet al. indicate how a usability evaluation may be specified. Eachpotential usability method is briefly introduced with an indicationof the information outputs, stage of application, resources andpeoplerequired. The paper culminates in an in-vehicle information systemsusability evaluation framework to demonstrate the main stagesinvolved. This framework shows the validation pathways as well asindicating which methods are most suited to different phases ofevaluation.

Bronstrom et al. draw the lines of tension between safety assess-ments and usability evaluation. They note that safety assessmentsoften take priority, but point out that safety and usability are notin conflict and are (more often than not) concerned with thesame aspects of interaction. In fact some definitions of usabilityhave safety as one of its criteria. Conversely, any assessment ofsafety is also likely to reference usability criteria (by virtue of thefact that a device that relates low on usability is likely to have safetyconcerns – such as it may cause distraction and absorb attentionalresources). In an assessment of the efficiency of a system, Bron-strom et al. found a good degree of concordance between reportsfrom users and expert evaluators. This provides encouragementfor use of the measures and the confidence that can be placed inthem. They argue that efficiency is a concept that subsumes bothusability and safety by measuring task completion time. Whilstsome may argue that this is only part of what is meant by usabilityit does provide a relatively rapid approach to system evaluationthat have proven links to customer feedback.

Mitsopoulos-Rubens et al. are concerned with the distractingeffect of in-vehicle information systems, and the potential effectsfor the safety of drivers and their passengers. Previous researchhas shown that operation of in-vehicle information systems canhamper performance on the primary driving tasks. Mitsopoulos-Rubens et al. propose that appropriate in-vehicle informationsystem interface design could reduce the demand on the driverand lead to improvements in driver performance. They comparedthree interfaces for a music player in a driving simulator: classic(i.e., a simple menu list), fisheye (i.e., main menu item in centrewith gradually shrinking items either side of it) and wheel (i.e.,inspired by the Apple iPod interface). They assessed driving perfor-mancewith the Lane Change Test andworkloadwith the NASA TaskLoad Index. The results revealed that the interfaces had little effecton driving performance as measured by the Lane Change Test. Norwere there any differences in the self-reported levels of workload.The only differences found were in the task times, where the drivertook longer with the fisheye interface. Mitsopoulos-Rubens et al.note that the Lane Change Test may not be sensitive to the differ-ences in demand of the different interfaces and that the tasks setto perform on the interfaces may not have been challenging enoughto disrupt the Lane Change Test.

Editorial / Applied Ergonomics 42 (2011) 529–532 531

Stanton et al. investigate the extent to which different interfacessupport the drivers understanding of in-path targets (e.g., othervehicles) detected by a radar-based Stop & Go Adaptive CruiseControl System. Three types of situation awareness were identifiedas pertinent to the study:modal awareness (understanding that thesystem is transitioning from following to cruising mode or viceversa, or that the system has acquired a new in-path target),temporal awareness (understanding the time to contact witha detected in-path target) and spatial awareness (understandingthe relative position of an in-path target). Driver responses to threeinterfaces (i.e., iconic interface, flashing iconic interface and radar-type display) were compared across the dimensions of situationawareness (i.e., the driver reported when a new in-path targethas been recognised by the system) and workload (self-reports ofmental, physical, temporal workload and performance, effort andfrustration). The results of the study showed that drivers weremore able to correctly identify which in-path targets had beendetected by the system with the radar-type display, but this wasaccompanied by reports of higher levels of workload and effort(Brookhuis et al., 2009).

4. Effects of driver distraction

Driver distraction is now widely recognised to be a significantroad safety issue (Regan et al., 2008). Three papers in the special issueare focused on the effects of driver distraction: Salmon et al. (Distrac-tion on the buses), Young et al. (Sensitivity of the Lane Change Test asa measure of in-vehicle system demand) and Edquist et al. (Effects ofadvertising billboards during simulated driving).

Salmon et al. argue that, as distraction is a major contributoryfactor in accidents in private passenger vehicles, it is also likely tobe a factor inpublic passenger vehicles. Unfortunately little researchhas been done to date, so the level of potential distraction whenoperating buses needs to be established. Unlike the private vehicle,bus drivers have additional tasks to perform (such as selling tickets,communicatingwith the control room, andmonitoring passengers),which may serve as additional sources of distraction. In order tounderstand the sources of distraction, Salmon et al. used a frame-work of methods comprising data collection (i.e., review of docu-ments, interviews with experts, focus groups, observationalstudies and ergonomic assessments), data analysis (i.e., contentanalysis, hierarchical task analysis, and error analysis) and outputs(i.e., identification of sources and effects of distraction). These anal-yses showed the range of tasks that bus drivers were involved in,including: preparation and pre-drive, vehicle control, routing, time-tabling, passenger-related, communication, and maintainingpersonal comfort. The results of the analyses reveal seven mainsources of distraction: technology, operational, passenger, environ-ment, cabin, infrastructure and personal. Thus it seems that theprofessional bus driver may be exposed to more sources of distrac-tion than private motor vehicle drivers. Salmon et al. argue that,before appropriate countermeasures be developed, much furthertargeted research is required, including the collection of data onbus drivers’ exposure to different sources of distraction and on theeffects of distraction on bus driver performance, and also researchto support the identification of the role of distraction in bus crashes.

Valid and reliable methods for assessing driver distraction arehighly important for research into the concept. Young et al. offerthe Lane Change Test as a method for assessing the distractivenature of operating in-vehicle systems. This could either replaceor supplement other tests such as the Visual Occlusion Technique(Gelau et al., 2009) or the Peripheral Detection Test if it proved tobe a reliable, valid and sensitive measure of distraction. The LaneChange Test is designed tomeasure the level of driving performancedegradationwhilst the participant driver is undertaking concurrent

secondary tasks on the in-vehicle system under assessment. Duringthe Lane Change Test, drivers are instructed to change lanes everytime a lane change sign appears at the side of the road. A numberof pertinent metrics are recorded covering lateral control, steeringangle and event detection as well as performance on the in-vehiclesystem. The study by Young et al. showed that the lateral controlmetrics were more sensitive than the event detection metrics. Ofthe lateral control metrics, the mean lane deviation was the mostsensitive to the visual and cognitive distraction of operating thein-vehicle system. Young et al. conclude with recommendationsfor further standardisation of the participant instruction protocoland refinement of the Lane Change Test methodology and analysis.

Edquist et al. consider the distractive effects of billboard adver-tisements on driving performance. Billboards compete for thedriver’s attention along with the road signage and other informa-tion in the world. In is no surprise that advertising is designed topurposely capture attention, but road-side usemay be an unwanteddistraction and could be implicated in some accidents. Edquist et al.developed a study to assess the level of distraction using the LaneChange Test (where drivers are required to change lanes inresponse to road signs). In the study, the lane change road signswere competing for the driver’s attention along with the billboardadvertisements (both static and dynamic advertisements weretested). The authors hypothesised that the billboard advertise-ments would hamper the driver’s response to the lane changerequests, and that this effect would be more marked for thedynamic advertisements. The results from the study in a drivingsimulator showed that the presence of billboard advertisementsdelayed the driver’s response to the Lane Change Test. This effectwas more marked for older drivers. There did not appear to beany differences between the static and dynamic advertisements,although the authors speculate that this could be due to the rela-tively simple nature of the advertisements being tested.

5. Conclusions for transportation safety

The papers presented in this special issue provide a contempo-rary overview of the status of ergonomics research in the area oftransportation safety. The following take-home messages can bedrawn from the papers in this special issue:

1. As well as an appropriate system of vehicle control, in-vehiclesystems have a key role to play in green driving; when designingsuch systems, careful consideration should be given to thepotential for driver distraction;

2. Careful consideration should be given to the design of in-vehiclesystem usability evaluations, both in terms of selecting appro-priate methods and in identifying the tasks and context inwhichthe evaluation will take place;

3. A systems approach, incorporating road infrastructure design,driver training, and in-vehicle systems, is required whendesigning countermeasures for intersection collisions;

4. Due to exposure to additional, work-related sources of distrac-tion, driver distraction is likely to be a problem in public trans-port settings;

5. Drivers are more likely to comply with level crossings if there isadvanced indication of the crossing together with informationabout oncoming trains and flashing red lights when a train iscoming through;

6. Communication of information to the driver is more likely to besuccessful if metaphorical approaches to the driver interface areused, such as communicating in-path vehicles using a ‘radar’metaphor;

7. Mean lane deviation in the Lane Change Test appears to be themost sensitive measure of driver distraction;

Editorial / Applied Ergonomics 42 (2011) 529–532532

8. Billboard advertisements compete with other driving-relevantinformation in the world for the driver’s attention and candistract the driver from the driving task.

9. Harmful exposure to vibration and shock when operating main-tenance vehicles in the railroad industry represents a key healthand safety issue. Some of the track maintenance vehiclescurrently used in this context exceed current whole-body vibra-tion guidelines for 8 h exposure duration in the vertical axis.

From these very specificmessages taken directly from the paperswithin the special issue, it is possible to draw some very generalpoints that can be applied across the transport domains, as follows:

1. The complexity of transportation system performance is suchthat frameworks or toolkits of ergonomics methods are requiredfor studying/evaluating human behaviour during transporta-tion-related activities;

2. A systems approach is required when designing countermea-sures in the transportation domains;

3. Simulation represents a key medium for evaluating humanbehaviour and new transportation systems;

4. Distraction is currently a highly popular concept within trans-port-related research; however, it requires further investigationin different contexts and domains (e.g. public transport);

5. New in-vehicle systems should be designed with careful consid-eration of their potential to distract drivers;

6. Occupational health and safety is an important issuerequiring further ergonomics investigation in the transporta-tion domains.

It is highly likely that transport will remain an importanttopic for research into the future, and one that Applied Ergo-nomics can make a valuable contribution. As Caple (2010)notes, there is a need to translate research findings into oper-ational practice. The research reported in this special issuehas been shown to have many practical applications, as wellas some generalisable findings than transcend transportationdomain boundaries.

Acknowledgement

Dr Paul Salmon’s contribution to this article and special issuewas undertaken as part of his Australian National Health andMedical Research Council Public Health postdoctoral trainingfellowship.

References

Aircraft CrashesRecordOfficewebsite, 2010.www.baaa-acro.com/ (accessed 13.09.10).Brookhuis, K.A., Driel, C.J.G., Hof, T., van Arem, B., Hoedemaeker, M., 2009. Driving

with a congestion assistant; mental workload and acceptance. Applied Ergo-nomics 40 (6), 1019–1025.

Cacciabue, P.C., Carsten, O., Tango, F., 2010. Driver modelling in automotive systems.Applied Ergonomics 41 (2), 177–178.

Caple, D.C., 2010. The IEA contribution to the transition of ergonomics fromresearch to practice. Applied Ergonomics 41 (6), 731–737.

Caser, S.M., 2009. Perceived vs. measured effects of advanced cockpit systems onpilot workload and error: are pilots’ beliefs misaligned with reality? AppliedErgonomics 40 (3), 448–456.

Chang, Y.-H., Yeh, C.-H., 2010. Human performance interfaces in air traffic control.Applied Ergonomics 41 (1), 123–129.

Dorrian, J., Baulk, S.D., Dawson, D., 2011. Work hours, workload, sleep and fatigue inAustralian rail industry employees. Applied Ergonomics 42 (2), 202–209.

Gelau, C., Henning, M.J., Krems, J.F., 2009. On the reliability of the occlusion tech-nique as a tool for the assessment of the HMI of in-vehicle information andcommunication systems. Applied Ergonomics 40 (2), 181–184.

Gstalter, H., Fastenmeier, W., 2010. Reliability of drivers in urban intersections. Acci-dent Analysis & Prevention 42 (1), 225–234.

Horberry, T., Inwood, C., 2010. Defining criteria for the functional assessment ofdriving. Applied Ergonomics 41 (6), 796–805.

Isler, R.B., Starkey, N.J., 2010. Evaluation of a sudden brake warning system: effect onthe response time of the following driver. Applied Ergonomics 41 (4), 569–576.

Mori, M., Horino, S., Kitajima, Ueyama, M., Ebara, T., Itani, T., 2008. Ergonomics solu-tion for crossing collisions based on field assessment of visual environment aturban intersections in Japan. Applied Ergonomics 39 (6), 697–709.

Regan, M.A., Lee, J.D., Young, K.L., 2008. Driver Distraction: Theory, Effects and Miti-gation. CRC Press, Boca Raton, Florida.

Roach, G.D., Darwent, D., Sletten, T.L., Dawson, D., 2011. Long-haul pilots use in-flightnapping as a countermeasure to fatigue. Applied Ergonomics 42 (2), 214–218.

Ryan, B., Wilson, J.R., Sharples, S., Morrisroe, G., Clarke, T., 2009. Developing a railergonomics questionnaire (REQUEST). Applied Ergonomics 40 (2), 216–229.

Sandin, J., 2009. An analysis of common patterns in aggregated causation chartsfrom intersection crashes. Accident Analysis & Prevention 41 (3), 624–632.

Stanton, N.A., Salmon, P.M., Harris, D., Marshall, A., Demagalski, J., Young, M.S.,Waldmann, T., Dekker, S., 2009. Predicting pilot error: testing a newmethodologyand amulti-methods and analysts approach. Applied Ergonomics 40 (3), 464–471.

Walker, G.H., Stanton, N.A., Kazi, T.A., Salmon, P.M., Jenkins, D.P., 2009. Doesadvanced driver training improve situational awareness? Applied Ergonomics40 (4), 678–687.

World Health Organisation, 2004. World Report on Road Traffic Injury Prevention.

Neville A. Stanton*

Transportation Research Group, School of Civil Engineering andthe Environment, University of Southampton,

Highfield SO17 1BJ, UK* Corresponding author.

E-mail address: n.stanton@soton.ac.uk.

Paul M. SalmonHuman Factors Group, Monash University Accident Research Centre,

Building 70, Clayton Campus, Monash University,Victoria 3800, Australia