Airport Location FactorsThe location of an airport site in the case of an isotropic plain
can be viewed as a balance between two opposing forces:
Benefits. The closer an airport is to the city center,
the more benefits are derived because of shorter average commuting
times from the airport to centers of activity. The airport is then
able to conveniently service a metropolitan area. The commuting
radius represents a tolerable commuting distance / time from the
city center, which is in the range of 1 hour. Beyond that threshold
an airport does not serve its metropolitan area well as an undue
amount of time must be spent to reach it. The integration of rail
systems with airport development, such as in Hong Kong and Paris,
reduces this friction of distance by connecting it efficiently to
the urban core. However, many airports, especially Narita and New
York-JFK, still have poor connections with their metropolitan areas
because of congestion and the lack of alternatives to road access.
Externalities. As the location of an airport gets closer
to the city center, more externalities are incurred. The opportunity
cost for the land devoted to the airport, the number of people adversely
affected by noise, and incompatibilities with local land uses all
rise. Externalities have been a strong factor in recent airport
development, such as Denver and Hong Kong. Under such circumstances,
an airport site should be as far as possible from the city center.
In the case of Hong Kong for instance, approximately 380,000 people
lived within the 65 dB noise contour of the old Kai Tak airport;
but no one lived within the 65 dB contour of the new airport when
it opened.
Suitability. Benefits and externalities functions tend
to be inversely proportional to the other. Consequently, a compromise
is sought by choosing a site that is close enough to provide
significant benefits and far enough to minimize externalities. A
location ring of high suitability is derived from an overlay of
the benefits and externalities curves.
