Background Twyford Down

the original a33 winchester bypass, designed 1930s standards, unsuitable modern traffic.

outline strategic planning route of later known m3 motorway had begun in late 1930s. route link london basingstoke, in order reduce pressure on a30. detailed planning first phase of construction, 40 miles (64 km) section, between sunbury on thames , popham, began in 1962-3. 26 miles (42 km) section, between lightwater , popham, a30 , a303 separated, opened in june 1971; followed sunbury lightwater section opened in july 1974. second phase extend motorway 10 miles (16 km) southwards between popham , winchester, ending @ compton. planning began first public inquiry held in 1971, set line of motorway, , second section opened in 1985. third , final phase extend motorway winchester southampton , m27 motorway, , northern part of section impact on winchester s bypass.

winchester had been traffic bottleneck many years several major routes passed through historic city centre, including a31, a33 , a34, smaller routes a272. in 1930s, by-pass planned east of city, passing west of st. catherine s hill, opening traffic on 1 february 1940. construction of had been controversial affected itchen valley , offered partial solution congestion, people calling instead by-pass north , west of winchester.

as 1930s road construction project, bypass built then-contemporary standards, including at-grade crossings @ bar end , @ hockley. time progressed, bypass became more , more of bottleneck roads around improved higher standards, particularly after opening of a33 chandler s ford bypass in 1968 , a34 king s worthy link following year, meant long distance traffic, opposed merely london southampton, using bypass. morgan morgan-giles described bypass utterly inadequate , dangerous, lives in or near winchester agree. accident figures appalling. therefore, new motorway somewhere relieve traffic urgently needed. crossing @ bar end grade separated in 1973, junction @ hockley remained key point of congestion.