Just as the number and extent of infrastructure systems are
complex, so are the goals that are pursued for any particular
infrastructure system. One common goal suggested is to ensure
‘sustainable’ infrastructure. One interpretation of sustainability
is simply to have facilities with great longevity. However, this is
often not a realistic goal. First, managers must be sensitive to
the amount of resources required to construct and maintain any
particular facility. Longevity requires greater capital investment
for initial construction. Second, the requirements for facilities
are likely to change over time. For example, the legal size and
weight of trucks can change over time (usually with an increase),
which may make existing bridges functionally obsolete since they
cannot support larger trucks. Third, the usage of facilities may
decline to such an extent that maintaining an existing facility is
not beneficial.
For most infrastructure systems, managers adopt a planning
horizon for longevity decision making. Such planning horizons can
vary from a short period (such as a year or two) to decades (for
infrastructures such as ports or buildings). Each organization
involved in infrastructure management may have its own
planning horizon for such decision making.
In practice, the goals for infrastructure management are complex
and multiple. Most critically, facilities are expected to provide
acceptable performance to a variety of users. For example, a local
roadway might accommodate a variety of motorized vehicles (such as
buses, cars, and trucks - moving or parked), bicycles and
pedestrians (particularly at intersections). Deterioration of the
facility can affect acceptable performance, as with the development
of potholes, uneven surfaces and cracking for pavement. Extreme
events such as earthquakes, hurricanes, flooding or terrorist
activities can require immediate attention and response.
Typically, goals for infrastructure management can be
categorized as economic, environmental and social. Economic impacts
include the direct and indirect costs of managing and operating the
infrastructure system, the economic development potential for the
system (including employment) and any user or non-user benefits
stemming from the system. Environmental impacts are associated with
ecological system uses, emissions to the environment (especially
toxic chemicals and greenhouse gas emissions), and non-renewable
resource use. Social impacts pertain to equity of benefits, social
justice and individual development (including employment). This
‘Triple Bottom Line’ of goals is common for many social
investments.