**Problem 6-Analysis**

Simple as they
may be, planning-level analyses such as the ones conducted in this problem
are powerful tools for the planner, designer, and engineer. Often, the
underlying objectives (i.e., the questions that are being asked and the
reasons the analyses are being undertaken) can be addressed with an adequate
level of accuracy and reliability by planning-level analysis methods. In
such cases, these first-order methods usually represent the most cost- and
time-efficient means for addressing the underlying objectives of the
investigation, and the increased accuracy available from more sophisticated
and complex methods is neither warranted nor needed.

It is important to
note that critical review and interpretation skills are necessary even when
applying such simple analysis methodologies as the planning-level techniques
described in this problem. Sub-problem 6d, in particular, illustrates how a
careful and critical review of the initial model outputs leads to a
different conclusion than the model initially suggested.

A particular
strength of the planning-level analysis methodology used in this problem is
its ability to guide the analyst to an appropriate intersection design. The
relationship between the intersection's geometric characteristics and
resultant operational performance measures is clearly delineated by this
method, making it a particularly useful tool for highway designers and
planners as well as operational engineers.