Most of the goods we consume are provided by the market but this is not the case with roads; there is no competitive market in the provision of road space. For most goods, if there is an under-supply, prices and profits rise to encourage further production and conversely, if there is an over-supply, prices and profits fall to discourage production. In some cases, the feedback may be long-term rather than short-term but, in the course of time, profitability and output figures will show if an investment is a waste of resources.
Unfortunately, there are no such feedback mechanisms with the provision and maintenance of road space. Governments are totally dependent upon the judgement of engineers, economists, planners and researchers to tell them when, where and how many roads should be built and to what standard they should be maintained.
This paper looks at current procedures for evaluating and appraising road projects.
International Workshop on Impact Evaluation and Analysis of transportation Projects in Developing Countries, Bombay, 13-16 December 1994. TRL - Crowthorne, UK. pp. 16