Transportation Human Factors Chapter 17

Automotive Human Factors Importance – over 40,000 fatalities per year in the US with 90% attributable to human error. Importance – over 40,000 fatalities per year in the US with 90% attributable to human error. Overview: Overview: –Task analysis of the of the roadway system –Critical issues – visibility, hazards & collisions, impaired drivers, training & selection, and automation

Task Analysis of the Vehicle Roadway System Tracking task – driving is a second order control with preview Tracking task – driving is a second order control with preview The multitasking environment – primary task is lane keeping and road hazard monitoring (primary visual attention lobe (PVAL). Secondary tasks are signs, radio, maps, etc. The multitasking environment – primary task is lane keeping and road hazard monitoring (primary visual attention lobe (PVAL). Secondary tasks are signs, radio, maps, etc. The cabin environment – simple user- friendly & displays should be of high contrast, interpretable, & easy to read The cabin environment – simple user- friendly & displays should be of high contrast, interpretable, & easy to read

Task Analysis of the Vehicle Roadway System

Visibility Anthropometry – seating adjustments and ability to reach adjustment controls Anthropometry – seating adjustments and ability to reach adjustment controls Illumination – night time risk of fatality is 10 times greater Illumination – night time risk of fatality is 10 times greater Signage Signage –Minimize visual clutter –Place consistently –ID signs clearly – shape, color, etc. –Efficient verbal signs Resource Competition Resource Competition

Resource Competition

Hazards and Collisions Control loss – icy roads, lane width, lapse of attention, etc. All directly related to bandwidth of correction which is related to speed (most critical factor) Control loss – icy roads, lane width, lapse of attention, etc. All directly related to bandwidth of correction which is related to speed (most critical factor) Hazard response – poor visibility or inattention. Key parameter is time to react (2-4 sec). Again speed is most critical factor Hazard response – poor visibility or inattention. Key parameter is time to react (2-4 sec). Again speed is most critical factor Speeding – in addition to the above two, increases distance before successful avoidance maneuver and increases damage impact Speeding – in addition to the above two, increases distance before successful avoidance maneuver and increases damage impact

Relationships of Hazard Response Components

Accident Solutions Slightly over 40,000 fatalities per year since 1993 with 20% increase in miles driven. Peak years 69, 70, & 72 had 55,500 per year. Slightly over 40,000 fatalities per year since 1993 with 20% increase in miles driven. Peak years 69, 70, & 72 had 55,500 per year. Compliance – strict law enforcement (speeding & seat belt use) Compliance – strict law enforcement (speeding & seat belt use) Protective Devices – seat belts & air bags Protective Devices – seat belts & air bags Sensing – 25% of accidents result from rear end collisions. Tailgating is primary cause. Devices are brake lights and their placement (possible amber on deceleration) Sensing – 25% of accidents result from rear end collisions. Tailgating is primary cause. Devices are brake lights and their placement (possible amber on deceleration)

North Carolina Seatbelt Law Enacted Sept 1985

Cognitive Factors in Driving Expectancy – People respond much slower to the unexpected Expectancy – People respond much slower to the unexpected Prediction – Highway design & traffic control devices should help the driver forecast what is coming up (positive guidance). Prediction – Highway design & traffic control devices should help the driver forecast what is coming up (positive guidance). Risk – Driver training & experience can help the driver in ascertaining the risk factor Risk – Driver training & experience can help the driver in ascertaining the risk factor

The Impaired Driver Fatigue – Problem is vigilance with low frequency events (surprises) Fatigue – Problem is vigilance with low frequency events (surprises) Alcohol (50% of fatalities) As low as.05% will impair. Interlocking devices? Alcohol (50% of fatalities) As low as.05% will impair. Interlocking devices? Age – Young & older drivers have more accidents. Youth (inexperience & risk taking) and Older (cognitive processing slows) Age – Young & older drivers have more accidents. Youth (inexperience & risk taking) and Older (cognitive processing slows)

Fatality Rates – Age & Gender

Training and selection programs have only limited success

Automobile Automation Collision monitors Collision monitors Automated navigation systems Automated navigation systems Global positioning systems Global positioning systems Driver monitors Driver monitors Intelligent Vehicle Highway System (IVHS) Intelligent Vehicle Highway System (IVHS)

Public Ground Transportation Statistically it is: Statistically it is: –30 times safer to take the bus –7 times safer to take a train or subway Important human factors issues is to induce behavioral change toward mass transit Important human factors issues is to induce behavioral change toward mass transit Trains & subways have rigid infrastructures while buses use the same roadway systems as cars Trains & subways have rigid infrastructures while buses use the same roadway systems as cars

Aviation Human Factors The Tasks – Multitask & higher order tasks like an auto driver’s tasks but more complex The Tasks – Multitask & higher order tasks like an auto driver’s tasks but more complex Tracking & flight control – Aircraft has 6 degrees of freedom while auto has 2 Tracking & flight control – Aircraft has 6 degrees of freedom while auto has 2 The displays – many more The displays – many more Flight Control Dynamics – Sluggish to overcome inertia in larger aircraft & some third order tasks Flight Control Dynamics – Sluggish to overcome inertia in larger aircraft & some third order tasks Axis Interactions Axis Interactions Aircraft pilots must follow strict procedures Aircraft pilots must follow strict procedures

Complexity of Tracking, Flight Control Dynamics, & Displays

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

Situation Awareness

Social Context On commercial jetliners a pilot is a member of a 2 or 3 man team On commercial jetliners a pilot is a member of a 2 or 3 man team Must interact with other teams – air traffic controllers, ground crews, cabin crew, etc. Must interact with other teams – air traffic controllers, ground crews, cabin crew, etc. Good communication is paramount Good communication is paramount –eg., it is better to say “your altitude is too low” rather than “have you checked your altitude lately” Aeronautical Decision Making (ADM) and Crew Resource Management (CRM) training is effective Aeronautical Decision Making (ADM) and Crew Resource Management (CRM) training is effective

ADM & CRM Training Results

Stress & Impairments Training & licensing qualifications are much more stringent Training & licensing qualifications are much more stringent High stress in student pilots High stress in student pilots Motion sickness in light aircraft Motion sickness in light aircraft Emergency situations can be very stressful Emergency situations can be very stressful Military pilots must carry out mission in hostile environment Military pilots must carry out mission in hostile environment

Aircraft Automation Auto pilot Auto pilot Head up displays Head up displays Highway in the sky Highway in the sky Lock on target assist Lock on target assist Collision alerts Collision alerts Flight management systems to optimize routes Flight management systems to optimize routes

Air Traffic Control Tasks Are Highly Stressful Controller is assigned an aircraft as it enters the controlled space Controller is assigned an aircraft as it enters the controlled space Insures safe and expeditious flow of aircraft in controlled space Insures safe and expeditious flow of aircraft in controlled space Interacts continuously with other controllers in the tower Interacts continuously with other controllers in the tower Communicates instructions to pilot while monitoring displays that ID locations of all aircraft in the controlled space Communicates instructions to pilot while monitoring displays that ID locations of all aircraft in the controlled space

Typical Air Traffic Control Display