4: How are highways designed?
101 -- Understand the term and how blueprints are
Viewpoints -- Learn about the various viewpoints and
how they are used in road construction.
C. Scale-down -- Review the definition
and reason for this in
D. Curves -- Read about the various
types of curves and how they
affect road design.
E. Access -- Understand the different
access designs used in road
F. Earthwork and Drainage -- Learn
why earthwork and drainage are
H. Unit 4 Glossary
-- Practice using the terms and definitions
included in this unit.
I. Unit 4 Activities
-- Activities will allow students to reinforce the
informational materials covered in this
Now that we have taken a look at how engineers
and planners decide where the highway should go, let's take a look at
how they are actually designed. We will also review some of the
issues that designers need to consider.
Highway designers create plans that are
used by contractors to build the roadway. The plans must be very
detailed and easy to read so the contractor builds what the designer
Construction plans used to be, and sometimes
still are, called blueprints because of the way plans used to
be copied. Originals were hand drawn on sheets of special paper
called vellum or special plastic called Mylar. These sheets were transparent,
or see-through, and would be laid on top of another special type of
paper called blue line paper. The blue line paper, which was
often yellow in color, was light-sensitive and when a bright light
was passed over the vellum or Mylar the areas that were clear turned
white and those with writing or drawing turned blue. That is
why they are called blueprints. Today plans are drawn on computer
and then printed or plotted.
4 B. Drawing Viewpoints