It provides the principal road connection to parts of the west and north of the county of Norfolk from Newmarket and points south of there, including London.
To the south of this junction the A11 and M11 provide a fast, dual carriageway and largely grade separated route as far as the outskirts of London.
After 3.5 miles (5.6 km), the large United States Air Force base at RAF Lakenheath is reached.
The road originally crossed what is now part of the airfield, and was diverted during World War II to run along the eastern perimeter fence of the base as far as Wangford, where it passes close to the end of the runway.
On this stretch the road passes close to Grimes Graves, a large Neolithic flint mining complex.