1 IE 486 Work Analysis & Design II Lecture 16 – Transportation Human Factors Dr. Vincent G. Duffy Thursday March 23, 2007

2 Lab 3, Lab 4 & Review for exam 2 Lab 3 can be turned in today or tomorrow for full credit. Lab 4 will be introduced tomorrow. Review for exam 2 will also begin tomorrow. Lab 3 will be included in the review discussion and on exam 2. Exam 2 will be held in class next Tuesday, March 27.

3 Transportation Human Factors Today: primarily Automotive & Public there are certain features of vehicles that make them stand apart from other systems –yet solutions incorporate ideas from other chapters Some statistics for consideration –every year 500,000 people die (worldwide) in autos –40,000 in the U.S. with a cost of $100 Billion/yr. –As high as 90% of accidents are human error issues include: visibility, hazards and collisions, impaired drivers, training & automation

4 Resource competition Predicting # of fatalities (FA) based on market penetration (MP) –Glance duration (GT), # of glances (G), frequency of use (FU) –And shows that we should balance benefits of any in-vehicle device with the potential fatalities that it may cause. FA = (1.019 ) (currentyear-1989) (MP)[ (GT) 1.5 (G)(FU)]

5 Further information on glance times

6 Automotive human factors Competing goals: –productivity - timely trip and safety deaths per year are relatively constant, but decreasing per passenger mile –and statistics of the whole population are quite different from those of young, old and males. The task includes –maintaining lane position - 2nd order control task –speed keeping - ‘longitudinal task’ (over time) a good measure of performance - estimated time to lane crossing

7 Tracking & control of a vehicle is related to performance capabilities and limitations. Performance can be considered through intermediate performance measures such as lane keeping, or others (hit/miss) such as hazard avoidance.

8 Driver’s information processing tasks Centered around the model presented in figure 17.1 In cab Road Side ViewingScanning Non-visual Tasks AuditoryMotor Cognitive Exit 2 Miles First order Tracking 2 nd Order Tracking TLC – time to lane crossingSecondary Tasks Primary task: Road Hazard Monitoring Forward Vision

9 Visual secondary tasks Electronic devices can act as sources of distraction –most common denominator of all visual attention - amount of time that visual resources are diverted away from primary visual attention Danger when time is larger than some minimum value amount of danger is proportional to vehicle speed suggestions for controls and ‘cabin’ environment are related to materials from chapters 4, 8 & 9 on visual systems, controls and displays

10 Speed and hazard Hazard response –estimated time to react to unexpected objects is important typical reaction time 2.5 seconds is significantly more than that found in traditional psychology experiments (in the laboratory) speed provides a quadruple threat increased likelihood of loss of control decreased probability of timely detection of hazard increased travel distance (in same time) increased damage at impact

11 Speed and hazard Small cars were more likely to be ‘rear-ended’ because they were perceived to be farther away p.445 Wickens; re: Evans study & previous notes; Eberts study average separation distance is 1.3 sec. While average minimum safe stopping is 2 sec. Drivers tend to believe they are less likely to be in an accident than the average driver related to bias & decision making from previous discussion – eg overconfidence (see p re: risky behavior)

12 Novel design solutions Affecting behavioral change - Carrot or the stick - which is more effective? –drivers were more likely to wear seatbelts if police officers randomly rewarded drivers for wearing seatbelts Mortimer, Goldsteen, Armstrong, Macrina, 1990, Effects of incentives and enforcement on the use of seatbelts by drivers, Journal of Safety Research, 21, System re-design – visual cues –Tri-light system - amber light turned on if ‘accelerator’ pedal is released rather than two light - off/brake light system –Shinar, 1995, Field evaluation of an advance brake warning system, Human Factors, 37 (4) Design should capitalize on expectancy –Eg. Traffic lights should be standardized according to speed of typical driver approach

13 Arguments about ‘adaptive’ drivers Consider risk homeostasis idea –hypothesis: antilock brakes enable people to driver faster or more recklessly thereby negating the safety advantage –automation could make drivers more complacent However, making wider lanes made significant improvements on safety Impairment can be from fatigue, alcohol & age –older drivers may drive more cautiously, slowly to avoid risk

14 Training… The ability of instructor to create emergency conditions is low in real environment hence, some benefits can be gained from simulators It is noted that there is little evidence to support the idea that mandatory drivers training programs improve safety And visual acuity tests don’t test critical skills such as vision of dynamic events night vision or visual attention skills

15 Public transportation – other cost considerations Generally 30times more safe to take the bus, 7times more safe to take the subway efforts needed to gain ‘behavioral changes’ include making travelers aware of lower risks, lower costs and greater efficiency of public transportation Relation between research and fatalities $ Research years of lost life traffic injuries 112M4.1M cancer, heart disease & stroke 1.5B 3.8M greater than 10x money spent for medical research

16 We sometimes will consider aspects of human factors and engineering such as controls, displays or safety, independent of the application domain. Here we will introduce safety in relation to the transportation application domain. Later we will revisit safety. For this Transportation Safety discussion, consider this supplementary 1 page of notes/ handout/book by Henderson,“100 Ways to live to be 100”. Section on Safety.