In 1997 the BTE used its Road Infrastructure Assessment Model (RIAM) to make strategic level forecasts of expenditure needs for investment and maintenance between 1998 and 2020. The forecasts covered non-urban roads and bridges on roads of national significance including the National Highway System. Expenditure needs were predicted for upgrading of road capacity (widening, adding lanes), new town bypasses, maintenance needs, and bridge replacements. Some types of investment had to be omitted because of data deficiencies or modelling difficulties. The exclusions were urban roads, flood mitigation projects, major realignment projects and widening roads used by road trains for safety reasons. Investments justified on social or equity grounds were also excluded. Total forecast expenditure needs for the National Highway System for the coming 22 year period were estimated at $16.8 billion of which the backlog comprised $2.6 billion. (A)
Samenvatting