Transportation Transportation Human FactorsHuman Factors

Chapter 17Chapter 17

Automotive Human Automotive Human FactorsFactors Importance – over 40,000 fatalities Importance – over 40,000 fatalities

per year in the US with 90% per year in the US with 90% attributable to human error.attributable to human error.

Overview:Overview:– Task analysis of the of the roadway Task analysis of the of the roadway

systemsystem– Critical issues – visibility, hazards & Critical issues – visibility, hazards &

collisions, impaired drivers, training & collisions, impaired drivers, training & selection, and automationselection, and automation

Task Analysis of the Task Analysis of the Vehicle Roadway Vehicle Roadway SystemSystem Tracking task – driving is a second order Tracking task – driving is a second order

control with previewcontrol with preview The multitasking environment – primary The multitasking environment – primary

task is lane keeping and road hazard task is lane keeping and road hazard monitoring (primary visual attention lobe monitoring (primary visual attention lobe (PVAL). Secondary tasks are signs, radio, (PVAL). Secondary tasks are signs, radio, maps, etc.maps, etc.

The cabin environment – simple user-The cabin environment – simple user-friendly & displays should be of high friendly & displays should be of high contrast , interpretable, & easy to read contrast , interpretable, & easy to read

Task Analysis of the Task Analysis of the Vehicle Roadway Vehicle Roadway SystemSystem

VisibilityVisibility Anthropometry – seating adjustments Anthropometry – seating adjustments

and ability to reach adjustment controlsand ability to reach adjustment controls Illumination – night time risk of fatality Illumination – night time risk of fatality

is 10 times greateris 10 times greater SignageSignage

– Minimize visual clutterMinimize visual clutter– Place consistentlyPlace consistently– ID signs clearly – shape, color, etc.ID signs clearly – shape, color, etc.– Efficient verbal signsEfficient verbal signs

Resource CompetitionResource Competition

Resource CompetitionResource Competition

Hazards and CollisionsHazards and Collisions Control loss – icy roads, lane width, lapse of Control loss – icy roads, lane width, lapse of

attention, etc. All directly related to attention, etc. All directly related to bandwidthbandwidth of correction which is related to speed (most of correction which is related to speed (most critical factor)critical factor)

Hazard response – poor visibility or inattention. Hazard response – poor visibility or inattention. Key parameter is Key parameter is time to react time to react (2-4 sec). (2-4 sec). Again speed is most critical factorAgain speed is most critical factor

Speeding – in addition to the above two, Speeding – in addition to the above two, increases distance before successful avoidance increases distance before successful avoidance maneuver and increases damage impactmaneuver and increases damage impact

Relationships of Relationships of Hazard Response Hazard Response ComponentsComponents

Accident SolutionsAccident Solutions

Slightly over 40,000 fatalities per year since Slightly over 40,000 fatalities per year since 1993 with 20% increase in miles driven. 1993 with 20% increase in miles driven. Peak years 69, 70, & 72 had 55,500 per year.Peak years 69, 70, & 72 had 55,500 per year.

Compliance – strict law enforcement Compliance – strict law enforcement (speeding & seat belt use)(speeding & seat belt use)

Protective Devices – seat belts & air bagsProtective Devices – seat belts & air bags Sensing – 25% of accidents result from rear Sensing – 25% of accidents result from rear

end collisions. Tailgating is primary cause. end collisions. Tailgating is primary cause. Devices are brake lights and their placement Devices are brake lights and their placement (possible amber on deceleration) (possible amber on deceleration)

North Carolina North Carolina Seatbelt Law Enacted Seatbelt Law Enacted Sept 1985 Sept 1985

Cognitive Factors in Cognitive Factors in DrivingDriving Expectancy – People respond much Expectancy – People respond much

slower to the unexpectedslower to the unexpected Prediction – Highway design & traffic Prediction – Highway design & traffic

control devices should help the driver control devices should help the driver forecast what is coming up (forecast what is coming up (positive positive guidanceguidance))..

Risk – Driver training & experience Risk – Driver training & experience can help the driver in ascertaining can help the driver in ascertaining the risk factorthe risk factor

The Impaired DriverThe Impaired Driver

Fatigue – Problem is vigilance with low Fatigue – Problem is vigilance with low frequency events (surprises)frequency events (surprises)

Alcohol (50% of fatalities) As low Alcohol (50% of fatalities) As low as .05% will impair. Interlocking as .05% will impair. Interlocking devices?devices?

Age – Young & older drivers have Age – Young & older drivers have more accidents. Youth (inexperience more accidents. Youth (inexperience & risk taking) and Older (cognitive & risk taking) and Older (cognitive processing slows) processing slows)

Fatality Rates – Age & Fatality Rates – Age & GenderGender

Training and selection Training and selection programs have only programs have only limited successlimited success

Automobile Automobile AutomationAutomation Collision monitorsCollision monitors Automated navigation systemsAutomated navigation systems Global positioning systemsGlobal positioning systems Driver monitorsDriver monitors Intelligent Vehicle Highway Intelligent Vehicle Highway

System (IVHS)System (IVHS)

Public Ground Public Ground Transportation Transportation

Statistically it is:Statistically it is:– 30 times safer to take the bus30 times safer to take the bus– 7 times safer to take a train or subway7 times safer to take a train or subway

Important human factors issues is to Important human factors issues is to induce behavioral change toward mass induce behavioral change toward mass transit transit

Trains & subways have rigid Trains & subways have rigid infrastructures while buses use the infrastructures while buses use the same roadway systems as carssame roadway systems as cars

Aviation Human Aviation Human FactorsFactors The Tasks – Multitask & higher order tasks The Tasks – Multitask & higher order tasks

like an auto driver’s tasks but more complexlike an auto driver’s tasks but more complex Tracking & flight control – Aircraft has 6 Tracking & flight control – Aircraft has 6

degrees of freedom while auto has 2degrees of freedom while auto has 2 The displays – many moreThe displays – many more Flight Control Dynamics – Sluggish to Flight Control Dynamics – Sluggish to

overcome inertia in larger aircraft & some overcome inertia in larger aircraft & some third order tasksthird order tasks

Axis InteractionsAxis Interactions Aircraft pilots must follow strict proceduresAircraft pilots must follow strict procedures

Complexity of Tracking, Complexity of Tracking, Flight Control Dynamics, & Flight Control Dynamics, & DisplaysDisplays

Situation AwarenessSituation Awareness

Pilot must have an understanding & Pilot must have an understanding & awareness of location & implications of awareness of location & implications of future hazards – display design is of utmost future hazards – display design is of utmost importanceimportance

Situation AwarenessSituation Awareness

Social ContextSocial Context

On commercial jetliners a pilot is a member of On commercial jetliners a pilot is a member of a 2 or 3 man teama 2 or 3 man team

Must interact with other teams – air traffic Must interact with other teams – air traffic controllers, ground crews, cabin crew, etc.controllers, ground crews, cabin crew, etc.

Good communication is paramountGood communication is paramount– eg., it is better to say “your altitude is too low” eg., it is better to say “your altitude is too low”

rather than “have you checked your altitude rather than “have you checked your altitude lately”lately”

Aeronautical Decision Making (ADM) and Crew Aeronautical Decision Making (ADM) and Crew Resource Management (CRM) training is Resource Management (CRM) training is effectiveeffective

ADM & CRM Training ADM & CRM Training ResultsResults

Stress & ImpairmentsStress & Impairments

Training & licensing qualifications Training & licensing qualifications are much more stringentare much more stringent

High stress in student pilotsHigh stress in student pilots Motion sickness in light aircraftMotion sickness in light aircraft Emergency situations can be very Emergency situations can be very

stressfulstressful Military pilots must carry out Military pilots must carry out

mission in hostile environmentmission in hostile environment

Aircraft AutomationAircraft Automation

Auto pilotAuto pilot Head up displaysHead up displays Highway in the skyHighway in the sky Lock on target assistLock on target assist Collision alertsCollision alerts Flight management systems to Flight management systems to

optimize routesoptimize routes

Air Traffic Control Air Traffic Control Tasks Are Highly Tasks Are Highly StressfulStressful Controller is assigned an aircraft as it Controller is assigned an aircraft as it

enters the controlled spaceenters the controlled space Insures safe and expeditious flow of Insures safe and expeditious flow of

aircraft in controlled spaceaircraft in controlled space Interacts continuously with other Interacts continuously with other

controllers in the towercontrollers in the tower Communicates instructions to pilot while Communicates instructions to pilot while

monitoring displays that ID locations of monitoring displays that ID locations of all aircraft in the controlled spaceall aircraft in the controlled space

Typical Air Traffic Typical Air Traffic Control DisplayControl Display