CHAPTER 8: Engineering Psych
Fire Truck Color
-Red may be the traditional color of fire engines, but human factors and
ergonomics research finds that lime-yellow fire vehicles are less likely to be
involved in accidents.
-This research shows that because the color-transmitting cones in our eyes
don't work well in the dark, some colors are easier for us to see at night. We
are most sensitive to greenish-yellow colors under dim conditions, making
lime shades easiest to see in low lighting.
-A 2009 study by the U.S. Fire Administration (USFA), a division of the
Federal Emergency Management Agency (FEMA), also concluded that
fluorescent colors, including yellow-green and orange, are easiest to spot in
-However, later studies have qualified these findings. While the 2009 USFA
study confirmed that fluorescent yellow-green and orange may increase
vehicle visibility, the report also concluded that recognizing the vehicle was
more important than paint color. Therefore, if people in a particular
community don't associate the color lime with fire trucks, then yellow-green
vehicles may not actually be as conspicuous as intended.
-The U.S. Fire Administration reported that motor vehicle accidents were the
cause of more than 10 percent of firefighter deaths in 2012. Additionally,
such accidents can also injure or kill civilians
Third Break Light
-The gadget was a third brake light, mounted in the base of rear windshields
so that when drivers pressed their brakes, a triangle of light warned
following drivers to slow down
-At the end of a 10-month experiment, taxis with a third brake light had
suffered 60.6 percent fewer rear-end collisions than had the control-group
taxis. Additionally, drivers of taxis with the third brake light that were struck
in the rear by other vehicles were injured 61.1 percent less often than were
drivers of taxis without the light, and repairs to all taxis with the light cost
61.8 percent less than did repairs to taxis without the light.
-A third brake light provides an extra signal to distracted drivers and
studies confirm that it reduces automobile accidents.
-these lights reduced rear impacts by 4.3 percent.
-Although less dramatic than the original findings, this means that since the
lights became standard equipment, there have been about 200,000 fewer crashes, 60,000 fewer injuries, and more than $600 million in property
damage saved every year
-Preliminary data suggest that LED lights may reduce crashes.
Shared Mental Models
It's often the case that soldiers and other military personnel are required to
work in groups or teams. Frequently, these group members are lacking the
time needed to make decisions; instead, quick judgments must be made
with little opportunity for communication. In such scenarios, how do military
teams function effectively?
Your final reading is about a construct called a shared mental model. Mental
models are people's organization of knowledge about a particular topic. For
example, in driving a car, you know that the key must first go into the
ignition, the foot must be on the brake, then the car can be put into reverse
or drive. This is a small piece of your own mental model about driving or, in
other words, the way you organize your knowledge about driving. We
develop mental models about all sorts of different topics.
When group members have similar mental models, they are said to have a
shared mental model. One of the benefits of