 The greater part of the road was originally planned in the 1920s as a relief road linking London with South West England.Construction began in 1928 and the road, together with Chiswick and Twickenham Bridges, was opened in 1933.The section between Hanworth and Sunbury is part of an older route; before being widened and renamed Country Way in the 1970s, this section had the names Twickenham Road (between Apex Corner and Bear Road) and Sunbury Road (between Bear Road and Kempton Park).