§ Mr. SpearingTo ask the Secretary of State for Transport what is the latest available official estimate of the number of billion passenger car miles travelled in Greater London, together with the source; and what means he has available for maintaining subsequent measurements of that figure.
§ Mr. Peter BottomleyAbout 25 billion passenger car miles were travelled in London in 1986. This estimate, which will be updated periodically, is derived as follows
14 billion car miles (source: On-going National Traffic census)× 1.77 passenger per car (source: 1985–86 National Travel Survey)= 25 billion passenger miles.The estimate of car mileage is provisional pending completion of work on a new series drawing on data from the national traffic census and other sources including surveys which the Department of Transport continued on abolition of the GLC. Methods of restructuring traffic surveys in London to support more accurate monitoring of year on year changes are also being studied.