selection. This should be a useful help in the policy-making process as policy makers
often decide by trading off the objectives of some groups for those of others.
However, too many plan impacts may hinder effective decision-making. As
environmental effects may easily include dozens of physical and subjective parameters, it may not be easy to evaluate trade-offs among EQ and NED objectives.
Furthermore, all EQ objectives can rarely be considered simultaneously. Thus, the
formulation of an EQ plan which results in sharply reduced NED benefits compared
to the NED plan may cause a bias against the EQ alternatives.
14.4.2 Quantifying Infrastructure Planning Objectives
If the planner is able to translate objectives into operationally meaningful, quantitative parameters, multiobjective infrastructure planning can become successful.
When objectives are not tangible nor can be quantified, it becomes much more
difficult to systematically evaluate the trade-offs. However, mathematical modelling
techniques can only be used with quantifiable objectives.
Both monetary and/or nonmonetary scales can be used to quantify planning
objectives. Monetary costs and benefits can be measured with more accuracy, even
when market prices do not reflect the true social benefits and costs or do not exist at
all for objectives. The methods developed for assessing recreation demands and the
monetary benefits associated with recreational use of infrastructure projects provide
the appropriate illustration.
Quantitative indicators for the nonmonetary objectives of infrastructure planning
which are acceptable and meaningful to decision makers, the public and the planner,
are difficult to identify. Objectives which mostly relate to the public form part of the
policy-making process through a selection of appropriate numerical indicators. In
multiobjective planning, there are many possible parameters or methods which the
planner can use in order to minimise the risk of bias towards the more easily
quantifiable objective of economic efficiency.
14.4.3 Mathematical Models for Multiobjective Planning
The general multiobjective planning problem is the choice of the decision variables,
X ¼ (x 1 , x 2 ,. . .,x L ), expressed as a vector representing project or plan outputs, the
resources as inputs, and policies for project or plan operation.
Certain technical relationships among variables, g i (X) = 0, i ¼ 1, 2, . . ., m,
constrain planning alternatives or define the limits of technical feasibility.
Single-objective models built for the purpose of helping in the selection of the
best solution rest on the assumption that given the decision makers’ preferences, it is
possible to use a single-objective function F(X) to express them. The value of F(X)
for a specific solution vector X then gives the utility of X for the decision maker. In
14.4 Infrastructure Planning Objectives
389
often decide by trading off the objectives of some groups for those of others.
However, too many plan impacts may hinder effective decision-making. As
environmental effects may easily include dozens of physical and subjective parameters, it may not be easy to evaluate trade-offs among EQ and NED objectives.
Furthermore, all EQ objectives can rarely be considered simultaneously. Thus, the
formulation of an EQ plan which results in sharply reduced NED benefits compared
to the NED plan may cause a bias against the EQ alternatives.
14.4.2 Quantifying Infrastructure Planning Objectives
If the planner is able to translate objectives into operationally meaningful, quantitative parameters, multiobjective infrastructure planning can become successful.
When objectives are not tangible nor can be quantified, it becomes much more
difficult to systematically evaluate the trade-offs. However, mathematical modelling
techniques can only be used with quantifiable objectives.
Both monetary and/or nonmonetary scales can be used to quantify planning
objectives. Monetary costs and benefits can be measured with more accuracy, even
when market prices do not reflect the true social benefits and costs or do not exist at
all for objectives. The methods developed for assessing recreation demands and the
monetary benefits associated with recreational use of infrastructure projects provide
the appropriate illustration.
Quantitative indicators for the nonmonetary objectives of infrastructure planning
which are acceptable and meaningful to decision makers, the public and the planner,
are difficult to identify. Objectives which mostly relate to the public form part of the
policy-making process through a selection of appropriate numerical indicators. In
multiobjective planning, there are many possible parameters or methods which the
planner can use in order to minimise the risk of bias towards the more easily
quantifiable objective of economic efficiency.
14.4.3 Mathematical Models for Multiobjective Planning
The general multiobjective planning problem is the choice of the decision variables,
X ¼ (x 1 , x 2 ,. . .,x L ), expressed as a vector representing project or plan outputs, the
resources as inputs, and policies for project or plan operation.
Certain technical relationships among variables, g i (X) = 0, i ¼ 1, 2, . . ., m,
constrain planning alternatives or define the limits of technical feasibility.
Single-objective models built for the purpose of helping in the selection of the
best solution rest on the assumption that given the decision makers’ preferences, it is
possible to use a single-objective function F(X) to express them. The value of F(X)
for a specific solution vector X then gives the utility of X for the decision maker. In
14.4 Infrastructure Planning Objectives
389