The Effects of Commercial Electronic Variable Message Signs ...

Method Ref. # Advantages Disadvantages
3.2.1 Participant: selected,
sampled
3.2.2 Experimenter: absent;
remote observation; known to
participant
3.2.3 Stimuli: natural, ordinary,
in context; variable,
uncontrolled
3.2.4 Responses: crash
precursors; antecedent vehicle
and participant behaviors; more
frequent events
3.2.5 Scenario: natural route
and trip purpose; uses own
vehicle
3.3 On-road instrumented
vehicle
3.3.1 Participant: selected,
sampled
3.3.2 Experimenter: present;
direct observation and
interaction
3.3.3 Stimuli: selected; natural,
in context
3.3.4 Responses: crash
precursors; antecedent vehicle
and participant behaviors; more
frequent
3.3.5 Scenario: natural route,
artificial trip purpose; uses
experimental vehicle
3.4 Closed-course test track
79, 78,
42
79, 78,
42
79, 78,
42
79, 78,
42
79, 78,
118, 42
14
Know participant sample. Possible sampling bias.
56
Possible artificial participant
behaviors.
Natural stimuli. Stimuli not uniform; e.g.,
weather effects.
More frequent events than
crashes; can collect more
data with less risk.
Mostly natural experimental
context; uses own or longterm
borrowed vehicle.
Crash precursors only indirect
indicators.
Participant aware of test status;
may be injured or killed; vehicle
may be damaged or destroyed;
expensive.
54, 18 Know participant sample. Possible sampling bias.
83 More experimenter control;
increased experiment safety.
Possible artificial participant
behaviors.
83, 18 Natural stimuli. Stimuli not uniform; e.g.,
weather effects.
54, 18 More frequent events than
crashes; can collect more
data with less risk.
54, 83,
18
Semi-natural experimental
context; more safe.
Crash precursors only indirect
indicators.
Artificial trip purpose;
unfamiliar vehicle.