Iowa DOT's
policy is to be
sensitive to the environment
and foster and enhance
environmental stewardship.
IOWA DEPARTMENT OF TRANSPORTATION
Presents
ROCKS AND ROADS
Unit 3: Why isn't the highway straight?
We have learned about the geologic processes that shape the surface of Iowa, and we have learned how earth materials are used to build highways. Let's take a few minutes to discuss the function of highways and the process it takes to plan them.
A. What
are highways? -- Learn about the
transportation
network.
B. Who
decides where highways are built?
How do they make the
decisions?-- Understand who works
together to build
highways.
C. Who
takes care of the highways? --
Learn who is responsible
for the maintenance of the highway after
it is built.
D. Why
aren't highways always straight?
-- Understand the
process of road design.
E. Summary
F. Unit
3 Glossary -- Practice using the
terms and definitions
included in this unit.
G. Unit
3 Activities -- Activities will
allow students to reinforce
the informational materials covered
in this unit.
A highway is a road that is designed to carry traffic at high speeds. Highways are part of a transportation network that links cities, states, and even different countries. Other parts of the transportation network include railroads, airplanes and boats. This transportation network enables the quick movement of people and goods from one place to another.
Another aspect of the highway system often forgotten is the need for national defense. Our current Interstate Highway System was originally constructed by the Department of Defense to allow rapid troop movement.
TO: Unit 3 B. Who decides where higways are built?
How do they make the decisions?
