The severe restrictions on traffic in Oxford city centre mean that it is the only practical way for long-distance traffic to get past Oxford, especially as there are few road bridges over the rivers Isis and Cherwell.
In 1938 the southern part of the western section was opened from the bottom of Hinksey Hill to Botley.
In 1962 it was extended north by a new bridge over the River Thames to Wolvercote, and the whole western section then became part of the A34.
The ring road has suffered major problems in recent years as housing developments are built next to the ring road leading to more traffic light intersections and roadworks.
The rebuilding process involves several utility diversions and also building over a major railway line and two Thames tributaries[5]