asked the Secretary of State for Transport if he will publish for every year since 1970 (a) the actual percentage increases in national traffic growth in vehicle kilometres, (b) the forecast percentage increases for the above and (c) the difference between (a) and (b) above in percentage terms.
National traffic forecasts are revised from time to time, and the figures in the following table for each year are those from the latest forecast then available.Since 1975 the Department has published a range of forecasts. In years in which actual growth has fallen outside the forecast range, the difference has been calculated from the nearest point in the range.The national traffic forecasts are long term and do not attempt to predict year to year variations which may be induced by such factors as winter weather, sharp changes in the price or availability of petrol and so on. The figures shown are deduced from longer term trends. Moreover, it is the cumulative effect of growth over a period of years which matters, and actual traffic in recent years has remained within the forecast range.
|Year on year changes in actual and forecast traffic|
|Actual||FT orecast||Actual Less Forecast|
|Actual||FTorecast||Actual Less Forecast|
asked the Secretary of State for Transport what were the high and low estimates for national traffic growth calculated by his Department (a) for 1981 when the forecast growth for 1976 to 1985 was first published and (b) for 1982 when the forecast growth for 1979 to 1985 was first published.
The right hon. Gentleman's question does not make it entirely clear which figures he seeks. Forecast growth for 1976 to 1985 was covered in my Department's interim memorandum, which was published in 1978 and covered the period 1976 to 2005. The forecast average annual rate of growth—compound—for 1976 to 1985 in that document was 2 per cent. to 3 per cent. Forecast growth for 1979 to 1985 was covered in the "National Road Traffic Forecasts 1980", which covered the period 1979 to 2010. The forecast average annual rate of growth—compound—for 1978 to 1985 in that document is 1 per cent. to 2 per cent. The period 1979 to 1985 was not specified.
asked the Secretary of State for Transport whether the national traffic forecasts made by his Department are revised constantly in the light of actual traffic growth; and, if so, whether the revised forecasts are being used to reassess the need for current and planned trunk roads.
The performance of the forecasts is monitored continuously and they are revised when necessary. The latest available forecasts are used at each stage of the assessment of a trunk road. Those now in use were published in July 1980.