Geography Reference
In-Depth Information
Houston and Portland are diametrically opposed. Although the strengthening of
zoning regulations adopted for metropolitan areas in 1997 was not fully felt by the
2000 census, the difference of urban sprawl between the two cities is significant.
Between 1970 and 2000, the standard distance between the population and the
barycenter of the Houston metropolitan area increased by 2.8 km. Over the same
period, the increase was only 1.1 km for metropolitan Portland (see Figure 8.29).
Population growth was more moderate in Portland (80%) than in Houston (110%).
Even taking this into account, if urban sprawl had followed the average of the other
major US cities, the expected increase would climb to 1.7 km in Portland. With a
30-year population increase of 80% (2% growth per year), the metropolitan area of
Portland is noteworthy for its resistance to sprawl, a subject which we will return to
below.
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Figure 8.30.
Portland-Salem CMSA, population growth, 1970-2000
The “capital of good planning” [OZA 04], as Portland has come to be known,
was not completely untouched by urban sprawl. The city center population in 2000
remained static with regard to its 1970 boundaries, while growth occurred in areas
where the population had more than doubled (see Figure 8.30). The density profile
of the metropolitan area in 2000 was low at 14 inhabitants/ha in the city center and
13 inhabitants/ha for the metropolitan area, values which are almost as low as
Houston and far from the break-even threshold for effective light public
transportation. With the 2000 census showing about 5% of trips made by public
transport versus 89% by private motor vehicles, Portland is in the national average,
and lags behind cities less universally praised for their public transit development
strategies, such as Pittsburgh where public transit supplies 7.6% of all trips, which is
the highest rate among cities of comparable size.
