The A418 road is a main trunk road

Trunk road

A trunk road, trunk highway, or strategic road is a major road—usually connecting two or more cities, ports, airports, and other things.—which is the recommended route for long-distance and freight traffic...

 in Buckinghamshire

Buckinghamshire

Buckinghamshire is a ceremonial and non-metropolitan home county in South East England. The county town is Aylesbury, the largest town in the ceremonial county is Milton Keynes and largest town in the non-metropolitan county is High Wycombe....

 and Oxfordshire

Oxfordshire

Oxfordshire is a county in the South East region of England, bordering on Warwickshire and Northamptonshire , Buckinghamshire , Berkshire , Wiltshire and Gloucestershire ....

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

. It begins at a roundabout with the A4146

A4146 road

The A4146 is an A-class road running through south-central England from M1 Junction 14 at Milton Keynes, around Linslade and Leighton Buzzard , and via Dagnall to Hemel Hempstead, where it terminates at a roundabout with the A4251.In Milton Keynes, the road briefly follows the H6 Childs Way from...

 just north of Ascott

Ascott, Buckinghamshire

Ascott is a hamlet and country house in the parish of Wing, Buckinghamshire, England. The hamlet lies completely within the boundary of the Ascott Estate; it is home to many of the estate and house staff....

, near Leighton Buzzard

Leighton Buzzard

-Lower schools:*Beaudesert Lower School - Apennine Way*Clipstone Brook Lower School - Brooklands Drive*Greenleas Lower School - Derwent Road*Dovery Down Lower School - Heath Road*Heathwood Lower School - Heath Road*Leedon Lower School - Highfield Road...

. It then runs south as a single carriageway through Wing

Wing, Buckinghamshire

Wing is a village and civil parish in Aylesbury Vale district in Buckinghamshire, England. The village is on the main A418 road between Aylesbury and Leighton Buzzard...

 to Aylesbury

Aylesbury

Aylesbury is the county town of Buckinghamshire in South East England. However the town also falls into a geographical region known as the South Midlands an area that ecompasses the north of the South East, and the southern extremities of the East Midlands...

. This stretch is proposed for a dual carriageway bypass. After diving through Aylesbury the road runs past Aylesbury College before heading out into Stone

Stone, Buckinghamshire

Stone is a village in Buckinghamshire, England. It is located southwest of the town of Aylesbury, on the A418 road that links Aylesbury to Thame...

. From here it runs past Haddenham

Haddenham, Buckinghamshire

Haddenham is a large village and is also a civil parish within Aylesbury Vale district in Buckinghamshire, England. Its estimated population in 2011 is 8,385 It is about south-west of Aylesbury and north-east of Thame.-History:...

 to the M40

M40 motorway

The M40 motorway is a motorway in the British transport network that forms a major part of the connection between London and Birmingham. Part of this road forms a section of the unsigned European route E05...

 near Thame

Thame

Thame is a town and civil parish in Oxfordshire, about southwest of the Buckinghamshire town of Aylesbury. It derives its toponym from the River Thame which flows past the north side of the town....

. The road has been rerouted in two locations so that it no longer runs through Hulcott

Hulcott

Hulcott is a village and civil parish in Aylesbury Vale district in Buckinghamshire, England. It is north of Aylesbury, off the road that runs between Bierton and Rowsham.The village toponym is derived from the Old English for "hovel-like cottage"...

 and Haddenham.

Settlements on the A418

From the A505 in Buckinghamshire:

• Ascott
  Ascott, Buckinghamshire
  Ascott is a hamlet and country house in the parish of Wing, Buckinghamshire, England. The hamlet lies completely within the boundary of the Ascott Estate; it is home to many of the estate and house staff....
  
  
• Wing
  Wing, Buckinghamshire
  Wing is a village and civil parish in Aylesbury Vale district in Buckinghamshire, England. The village is on the main A418 road between Aylesbury and Leighton Buzzard...
  
  
• Rowsham
  Rowsham
  Rowsham is a hamlet in the parish of Wingrave, in Buckinghamshire, England. It is located to the south of the main village on the A418 road that links Bierton with Wing.The hamlet name is Anglo Saxon in origin, and means 'Hrothwulf's home'...
  
  
• Bierton
  Bierton
  Bierton is a village in Buckinghamshire, England, about half a mile northeast of the town of Aylesbury. It is a mainly farming parish, 10 km² in size....
  
  
• Aylesbury
  Aylesbury
  Aylesbury is the county town of Buckinghamshire in South East England. However the town also falls into a geographical region known as the South Midlands an area that ecompasses the north of the South East, and the southern extremities of the East Midlands...
  
  
• Hartwell
  Hartwell
  Hartwell is a village in central Buckinghamshire, England. It is to the south of Aylesbury, by the village of Stone.The village name is Anglo Saxon in origin, and means "spring frequented by deer". In the Domesday Book of 1086 it was recorded as Herdeuuelle and Herdewelle.The ruined Hartwell...
  
  
• Stone
  Stone, Buckinghamshire
  Stone is a village in Buckinghamshire, England. It is located southwest of the town of Aylesbury, on the A418 road that links Aylesbury to Thame...
  
  
• Gibraltar
  Gibraltar, Buckinghamshire
  Gibraltar is a hamlet in the parish of Dinton-with-Ford and Upton in Buckinghamshire, England. It is located on the modern main road that links Aylesbury with Thame.The hamlet is named after the British dependency of Gibraltar....
  
  

In Oxfordshire:

• Thame
  Thame
  Thame is a town and civil parish in Oxfordshire, about southwest of the Buckinghamshire town of Aylesbury. It derives its toponym from the River Thame which flows past the north side of the town....
  
  
• North Weston
• Tiddington
  Tiddington, Oxfordshire
  Tiddington is a village about west of Thame in Oxfordshire, England. The village is on the A418 road between Thame and Oxford.Tiddington is in the civil parish of Tiddington-with-Albury, which is on the county boundary with Buckinghamshire. Historically Tiddington was a manor and hamlet of the...