This article discusses the most pertinent principles that underlie the preferred social cost-benefit analysis methodology to evaluate public road projects in South Africa. The 'cost' component of the analysis is the once-off investment cost sacrificed to establish a facility, and the 'benefit' component is the recurring reduction of disutility emanating from the operation, maintenance, and use of a facility. To determine future road-user benefits, the article develops a social surplus criterion that is termed 'socio-economic user surplus'. A procedure is provided of the way that social costbenefit analysis should be supplemented by the application of equity weighting, with a view to indicating both the expected allocative efficiency and distributive efficiency of a proposed road project. Lastly, the article discusses why the economic impacts that may stem from economically justified road projects are not considered in a social cost-benefit analysis.
OPSOMMINGIn hierdie artikel word die mees tersaaklike beginsels bespreek wat die metodiek van sosiale kostevoordeelontleding om openbare padprojekte in Suid-Afrika te evalueer, onderlê. Die 'koste'komponent van die ontleding is die eenmalige investeringskoste wat opgeoffer word om 'n fasiliteit te vestig. Die 'voordeel'-komponent van die ontleding is die herhalende vermindering van buitewerkstelling wat uit die bedryf, instandhouding, en gebruik van 'n fasiliteit spruit. Wat toekomstige padgebruikersvoordele betref, ontwikkel die artikel 'n sosiale surplusmaatstaf genaamd 'sosio-ekonomiese gebruikersurplus'. 'n Prosedure word voorsien waarvolgens sosiale kostevoordeelontleding met billikheidsweging aangevul behoort te word, om sowel toewysingsdoeltreffendheid as verdelings-doeltreffendheid van 'n voorgestelde pad projek te toon. Laastens bespreek die artikel waarom die ekonomiese impakte wat uit ekonomies geregverdigde padprojekte kan spruit nie in sosiale kostevoordeelontleding oorweging geniet nie.The incorporation of (a) external costs imposed by road supply and use on non-road users, and (b) distributive efficiency to complement allocative efficiency criteria in SCBA, and the addition of (c) positive spill-over effects in an economic impact analysis supplementary to SCBA, render application of the Scitovsky [12] reversal test superfluous. The warning by Graaff [4] -that "[t]he implications for cost-benefit analysis are quite devastating if the Scitovsky reversal test is ignored" -is counteracted by the incorporation and addition of the three analyses discussed in this work.