The following table lists the average cost in real terms of adding an extra lane to existing motorways, provided by publicly funded major schemes for the last 10 years.
Lane km added to HA motorway network Cost per km in real terms (£ million) 1996-97 51 7.0 1997-98 39 4.0 1998-99 0 0 1999-2000 0 0 2000-01 0 0 2001-02 0 0 2002-03 7 32.3 2003-04 21 13.3 2004-05 4 2.0 2005-06 32 6.2