ABSTRACT
This
study evaluates the Dynamic Message Signs (DMSs) use to dissipate incident
information on the freeways in Las Vegas, Nevada. It focuses on the DMSs
message timing, extent, and content, from the operators’ and drivers’
perspectives, considering the variability in drivers’ freeway experience.
Two-week incidents data with fifty-nine incidents, DMS log data, and responses
from a survey questionnaire were used. The descriptive analysis of the
incidents revealed that about 54% of the incidents had their information posted
on the DMSs; however, information of only 18.6% of the incidents was posted on
time. The posted information covered the incident type (54.2%), location
(49.2%), and lane blockage (45.8%), while the expected delay or the time the
incident has lasted are rarely posted. Further, the standard DMSs are the most
preferred sources of traffic information on the freeway compared to the travel
time only DMSs, and the graphical map boards. The logistic regression applied
to the survey responses revealed that regular freeway users are less likely to
take an alternative route when they run into congestion, given no other information is available. Conversely, when given
accurate information through DMSs, regular freeway users are about 2.9
times more likely to detour. Furthermore, regular freeway users perceive that
the DMSs show clear information about the incident location. Upon improving the
DMSs usage, 73% of respondents suggested that the information be provided
earlier, and 54% requested improvements on congestion duration and length information.
These findings can be used by the DMSs operators in Nevada and worldwide to
improve freeway operations.