Street-lighting projects selection: A rational decision making approach

The study presented in this paper represents a new and fresh approach to the problem of efficiently and optimally allocating scarce resources in the provision of public services—namely, street-lighting. The methodology developed is aimed at introducing more systematic and rational thinking in a way which is both technically and politically feasible. To the best of the author's knowledge, the study presents, for the first time, a procedure for the comprehensive quantitative estimate of the utility accruing from street-lighting. The utility value derived from each street-lighting project depends upon several factors, some of which can be technically assessed and others estimated only by subjective values.

In order to deduce the subjective values, the Delphi method was employed. This method permits derivation of subjective values for groups of interviewees whose assessments may reasonably be assumed to be crucial in determining the relative values of the objectives of the utility function. Those components of the utility function representing subjective values were identified and estimated.

The conventional practice, whereby residents have no explicit say in the planning of the lighting system in their city, was abandoned. Residents' value judgements concerning the relative importance of the objectives to be gained by the lighting system were incorporated into the planning process. An optimization model based on an integer programming algorithm was employed because it permits periodic (e.g. annual) selection of a set of indivisible projects to be realized during a given period. This enables maximum economic and social utility to be derived, subject to budgetary and technological constraints.

The selection process was extended and deepened so as to render it sensitive to benefit from economies of scale and external economies. The optimization process was carried out with the use of an IBM-MPS X (an integer programming algorithm). The methodology was applied to a large and diverse quarter in the city of Jerusalem that is divided into seven semi-homogeneous neighborhoods—in terms of their physical as well as their socio-economic and demographic characteristics. This represents a very different approach when compared to the conventional way in which the planning design and installation of street-lighting projects are currently carried out.