Sub-problem 5a - Page 3 of 3
Sub-problem 5a: Existing Analysis of 10-Mile Segment of
What other factors should be considered? The
service measures for a two-lane highway are dependent on the classification
of the facility. Two-lane highways are categorized primarily on the purpose
they serve in the transportation system. Class I highways are facilities
where speed is an important determinant of the quality of serviceómotorists
traveling on these facilities have an expectation and desire to travel at
relatively high speeds. For Class II highways, speed is not an important
determinant of the quality of service, and drivers are affected primarily by
the amount of time they spend following other vehicles. The service measures
that define LOS for Class I facilities include both percent time following
and speed. For Class II facilities, LOS is defined solely in terms of
percent time spent following.
What measure should be used to determine the
performance of the facility? Since U.S. 95 is currently a Class I
facility, we will focus on travel speed and percent time following.
Application of the HCM methodology indicates that the average
travel speed is 52.4 mph, it takes 11.5 minutes to traverse the total
10-mile segment, and the percent time spent following is 55.7%. This
translates into a level-of-service "C".
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