Team 4

Alan, Danielle, & Stephen

Observation

• Revealing a flushing mechanism

• Located in the Head in the Armory

• Instructions located on the top

Observation

• Problem: Top is approximately 62” from the floor

Observation

• Mean eye level for American Male is 64.7 inches

• Must be well above this to look down on the top. Most are at an oblique angle or below.

Observation

• Attempt to alleviate the issue on ground floor

VISUAL ATTENTION IN DRIVINGA study comparing novice and expert drivers

“Visual attention and the transition from novice

to advanced driver”

G. Underwood (2007). Ergonomics

Background

• 20% - 30% of accidents are due to inattentive driving– Smoking– Eating– Applying makeup– Looking for objects in vehicle– Looking at objects on roadside– PDA’s

The risk of an accident

increases dramatically if

an unexpected road event occurs

while the driver is distracted

Situation Awareness

• Driving environment is visually busy

• Need to control the vehicle and awareness of external events

• Experienced drivers have better situational awareness

Safe vehicle operation requires:

• Lane keeping• Maintenance of speed• Maintenance of heading• Monitoring for hazards• Accurate navigation

Differences between novice and experienced drivers

• Visual attention– Younger drivers pay less attention

• Mental model– Experienced drivers accumulate memories

• Scanning behaviors

– Experienced drivers scan more

Reviews

• Eye scanning elliptical area

• Scanning behavior increases with

experience

• Changes in traffic/road conditions:

– Novices not sensitive to

– Experienced drivers anticipate

Reviews cont.

• Eye scanning road conditions:– Experienced drivers do– Novices don’t

• Very experienced drivers (police) short fixed duration– mental model supports dismissal of irrelevant

information– greater sampling of visual environment

Why Novices Fail to Scan

• Perception

• Comprehension

• Prediction• Novices

– one level – only perceive• Experienced

– Comprehend and predict hazards

Press key when detecting hazard

Hazard Prediction Experiment

• Videos of novice and expert driving– Rural– Urban– Dual carriageway

Results

• Experienced and novice process videos differently

• Experienced greater horizontal scanning• Experienced scan paths sensitive to

environment-novices didn’t

• Novices interest in road ahead

Attending to Hazardous Events

• Maintain awareness of other vehicles

• Hazards cause “attention capture” of novices only

• Very experienced drivers seek out and monitor multiple hazards

Learning to Anticipate Hazards

• Novice drivers trained to scan and anticipate hazards

• Results– Trained subjects scanned more of scene– Scanning behavior changes persisted until re-

test months later

Conclusion• Inattention and distraction contribute to accidents

– Unlikely to detect unexpected event

• Novices restricted scanning behavior– Not a matter of higher workload– Novice mental model – no accurate estimate of hazards

• Expert Drivers Mental Model more active and efficient scanning– Quickly dismiss irrelevant– Anticipate hazards, scan accordingly

• Training alters novice scan patterns– Encourages more active visual attention– Fosters predictive ability to anticipate other drivers

CHAPTER 10Visual Environment: Measurement and Design

Vision and the Eye

• Description of the way the eye works

Retinal Adaptation

• Ability to change sensitivity based on ambient light

• Night driving with sudden oncoming headlights is example

• Additional lights at tunnel entry and exit

Photometric Terminology

• Luminous intensity

Candela (cd)– Power of a source to emit light in a particular

direction

Photometric Terminology

• Luminous flux

Lumen (lm)– Rate of flow of luminous energy

Photometric Terminology

• Luminance

cd/m2

– Light emitted by a surface

Photometric Terminology

• Illuminance

Lux (lx)– Amount of light falling on a surface

Photometric Terminology

• Reflectance

– Ratio of the luminance and illuminance at a surface

Task lighting

• Visual tasks require light to illuminate the task environment

Visual tasks require light

• Proper lighting is more important for older subjects than younger

• Documented productivity increases with higher illumination levels– cigarette rolling– leather working

Glare

• Increases task demands– more pronounced in older subjects

• Bright lights can cause “retinal afterimages”• Obscure the task environment in night

driving– Oncoming headlights– Street lights– Construction beacons

Lighting Design• Suitable level of illumination• Balance of surface luminance

– Driving• ambient lighting• external lighting• dashboard brightness

• Light uniformity over time– Dynamic domain like driving this can change frequently – Changes can impact night vision of drivers

• Avoid glare

Line of Sight

• Driver’s 360° line of sight is critical factor in vehicle design

• In industrial applications, adequate field of view could eliminate need for a ‘spotter”

• Improved field of view could support more efficient operations