The Effects of Commercial Electronic Variable Message Signs ...

Method Ref. # Advantages Disadvantages
3.4.1 Participant: selected,
sampled
3.4.2 Experimenter: present;
direct observation and
interaction
3.4.3 Stimuli: selected; out of
context
3.4.4 Responses: crash
precursors; antecedent vehicle
and participant behaviors; more
frequent
3.4.5 Scenario: unnatural route,
artificial trip purpose; uses
experimental vehicle
3.5 Commentary driving
3.5.1 Participant: selected,
sampled
3.5.2 Experimenter: present;
direct observation; extensive
interaction
3.5.3 Stimuli: selected; natural,
in context
3.5.4 Responses: extensive
driver commentary; running
verbal description; crash
precursors observable
3.5.5 Scenario: natural route,
artificial trip purpose
3.6 Non-vehicle based field
testing
3.6.1 Roadside interviews 14,
125, 85
136 Know participant sample. Possible sampling bias.
136 More experimenter control;
increased experiment safety.
57
Possible artificial participant
behaviors.
136 Semi-natural stimuli. Stimuli not uniform; some
possible control.
136 More frequent events than
crashes; can collect more
data with less risk.
136 Low probability of harm to
participant or vehicle.
Crash precursors only indirect
indicators.
Unnatural experimental context.
36 Know participant sample. Possible sampling bias.
36 More experimenter control;
increased experiment safety.
Possible artificial participant
behaviors.
36 Natural stimuli. Stimuli not uniform; e.g.,
weather effects.
Collect large amounts of
data; direct observation of
gross attention.
Semi-natural experimental
context; more safe.
Relatively easy; less
resources.
Commentary could interfere
with driving task; artificial task.
Artificial trip purpose.
Artificial, distal testing
environment.