The Effects of Commercial Electronic Variable Message Signs ...

5.3 STRUCTURE
As outlined above, the proposed research program consists of three stages. The first stage
focuses on determining the potential existence of harmful distraction effects due to CEVMS. The
second stage involves determining limitations or restrictions to CEVMS parameters which could
reduce or eliminate the implied potentially harmful distracting effects. The third stage focuses on
relating the reduction in implied potentially harmful distraction to actual safety benefits of
decreasing crashes, fatalities, injuries, and property damage on the roadway. The sections below
describe these stages in more detail.
5.3.1 Stage 1—Determination of Distraction
The first stage, to determine the potential existence of harmful CEVMS distraction, may be
implemented in many different ways. According to the analysis of research strategies in
section 4.0, the three most effective approaches are the on-road instrumented vehicle, the
naturalistic driving, and the unobtrusive observation methods.
The on-road instrumented vehicle method is sensitive to a wide range of variables, including
accurate eye glance measurements. It affords the opportunity to ensure that the test participants
drive by many CEVMS and comparison sites in a structured and reproducible manner.
The naturalistic driving method is similar to the on-road instrumented vehicle technique, but it
has less control since the test participants drive their own vehicles according to their own
personal daily schedules. As a result, the participants may pass few, if any, billboards.
Furthermore, the naturalistic driving method has difficulty supporting accurate eye glance
measurements, and it requires considerably more effort and expense. However, the naturalistic
driving method is less artificial and has a high degree of face validity.
Although the unobtrusive observation method also involves considerable effort and expense, the
data collected are based on the observation of vehicles rather than individual drivers. The
unobtrusive observation method is the least artificial of the three because with this technique,
research participants are generally unaware of being observed.
This first stage of the research program would employ one or more of these study approaches as
a first step. A single method could be selected, or more than one approach could be combined.
For example, the on-road instrumented vehicle and the unobtrusive observation method could
make an effective combination, but the cost would be high. In either case, this first stage should
also be designed to answer, at least in a preliminary manner to whatever degree possible, some of
the practical questions of interest to the community concerned with outdoor advertising control.
5.3.2 Stage 2—Basis for Regulation
If the results of the first stage reveal a CEVMS driver distraction effect sufficient for public
concern, then the second stage of the proposed research program would be implemented to
provide an initial technical basis for possible regulation. This stage would consist of a series of
eye glance and safety surrogate evaluations in the field and in the laboratory designed to
investigate the various parameters of CEVMS which contribute to driver distraction. Although
field methods can capture the realism of the CEVMS stimulus, they do not allow the researcher
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