Civil Engineering Reference
In-Depth Information
12 zones, road segments in the dozens, and no transit at all. Square City is
of interest to us because the City Mothers along with the City Fathers are
wondering whether a new bridge is needed.
As almost all the world's cities are parts of complex metropolitan trans-
portation networks, often with extensive suburbs, Square City is unusual, but
conveniently so. It has barely any suburbs. Conveniently, it is also square, so
it can be divided into four equal-sized internal zones and—to represent the
origins and destinations in the rest of the world—eight external zones, as
seen in figure 8.2. The river that is causing the bridge problem runs north
to south through the center of the city, dividing the NE and SE zones on
the east bank from the SW and NW zones on the west bank.
N
EXTERNAL
ZONE
EXTERNAL
ZONE
NE
ZONE
EXTERNAL
ZONE
EXTERNAL
ZONE
NW
ZONE
N2
N1
S1
S2
SE
ZONE
EXTERNAL
ZONE
EXTERNAL
ZONE
SW
ZONE
EXTERNAL
ZONE
EXTERNAL
ZONE
SQUARE CITY
Figure 8.2. Square City divided into Transportation Analysis Zones.
