Subproblem 1b - Page 2 of 5
Determining the Facility Class and Scope of the
Let's discuss each of these issues and how each affects
the operational analysis that we are about to complete.
Why is there a further distinction within facility
types? This question must be addressed separately
for the arterial and two-lane highway portions. We will begin with the
arterial portion. The need for various class types is important, because it represents
the driver's ability to travel at a desired speed while considering the
various influences on the urban street. In the case of a Class IV facility,
one might put less emphasis on arterial throughput and speed as compared to
a Class I facility; thus the level of service standards might be different
in each of these cases.
The two-lane highway is typically within a much more
rural environment; and the distinction separates roadways where drivers
expect to travel at high speeds (Class I), as compared to those facilities
that might provide more of a recreational function (Class II).
What parameters contribute to the
distinction? For urban streets (arterials), the parameters that
contribute to the distinctions include
the level of roadside development, posted speeds, cross section, pedestrian
activity, signal spacing or any other characteristics that would suggest
differences in motorist perception of the quality of service. It is these differences that
contribute to the slight disparities in running time, which are used to
provide an indication of travel speed.
For two-lane highways, it is primarily the length of the
trip, or type of trip that offers the distinction between the class type.
Are the segments under consideration homogenous
In our case, the facility is approximately seven miles long with nearly
equal signal spacing and no discernible differences in any of the other
characteristics that would influence motorist expectations. Therefore no
reasons can be offered for creating more than one facility for analysis
purposes. So the only question that remains is, what class should
be assigned to this facility? We have four classes from which to choose:
Class I: High speed
Class II: Suburban
Class III: Intermediate
Class IV: Urban
Based on what we know of the area, which of these classes
can we eliminate from further consideration?
[ Back ] [ Continue
] with Sub-Problem 1b