The A412 is a road in 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...

 that links Slough

Slough

Slough is a borough and unitary authority within the ceremonial county of Royal Berkshire, England. The town straddles the A4 Bath Road and the Great Western Main Line, west of central London...

 and Watford

Watford

Watford is a town and borough in Hertfordshire, England, situated northwest of central London and within the bounds of the M25 motorway. The borough is separated from Greater London to the south by the urbanised parish of Watford Rural in the Three Rivers District.Watford was created as an urban...

. It was previously the main artery for this corridor, prior to the construction of the M25

M25 motorway

The M25 motorway, or London Orbital, is a orbital motorway that almost encircles Greater London, England, in the United Kingdom. The motorway was first mooted early in the 20th century. A few sections, based on the now abandoned London Ringways plan, were constructed in the early 1970s and it ...

. It provides interchange to the A40

A40 road

The A40 is a major trunk road connecting London to Fishguard, Wales and officially called The London to Fishguard Trunk Road in all legal documents and Acts...

/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...

 at the Denham Roundabout

Denham Roundabout

The Denham Roundabout is a large road intersection to the west of London, at junction 1 on the M40 motorway.When Western Avenue was originally built, it ended at a point west of Uxbridge at the intersection of the road from Uxbridge towards Gerrards Cross and High Wycombe with the road from...

, the M25 in Maple Cross

Maple Cross

Maple Cross is a village in Hertfordshire, England with a large proportion of the housing being either council owned or previously council owned. The area is served by junction 17 of the M25 motorway, which makes up one of the boundaries of the village...

 and the A41

A41 road

The A41 is a formerly-major trunk road in England that links London and Birkenhead, although it has now largely been superseded by motorways. It passes through or near various towns and cities including Watford, Hemel Hempstead, Aylesbury, Solihull, Birmingham, West Bromwich, Wolverhampton,...

 north of Watford

Watford

Watford is a town and borough in Hertfordshire, England, situated northwest of central London and within the bounds of the M25 motorway. The borough is separated from Greater London to the south by the urbanised parish of Watford Rural in the Three Rivers District.Watford was created as an urban...

. In Watford the road links to the Watford Ring Road

Watford Ring Road

The Watford Ring Road is a road located in Watford, Hertfordshire, UK. It is numbered A411, and serves as a one way system around the town centre...

, and passes close to the town centre as a partially grade separated

Grade separation

Grade separation is the method of aligning a junction of two or more transport axes at different heights so that they will not disrupt the traffic flow on other transit routes when they cross each other. The composition of such transport axes does not have to be uniform; it can consist of a...

 dual carriageway.

Settlements on the A412

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....

:

• Slough
  Slough
  Slough is a borough and unitary authority within the ceremonial county of Royal Berkshire, England. The town straddles the A4 Bath Road and the Great Western Main Line, west of central London...
  
  
• Iver Heath
  Iver
  Iver is in the south-east corner of the English county of Buckinghamshire and it forms one of the largest civil parishes in the South Bucks district.Iver railway station is in Richings Park.-Etymology:...
  
  
• Denham
  Denham, Buckinghamshire
  Denham is a village and civil parish in the South Buckinghamshire district of Buckinghamshire, England. It is north west of Uxbridge and north of junction 1 of the M40 motorway. Denham contains the Buckinghamshire Golf Club.-Origin:...
  
  

Hertfordshire

Hertfordshire

Hertfordshire is a ceremonial and non-metropolitan county in the East region of England. The county town is Hertford.The county is one of the Home Counties and lies inland, bordered by Greater London , Buckinghamshire , Bedfordshire , Cambridgeshire and...

• West Hyde
• Maple Cross
  Maple Cross
  Maple Cross is a village in Hertfordshire, England with a large proportion of the housing being either council owned or previously council owned. The area is served by junction 17 of the M25 motorway, which makes up one of the boundaries of the village...
  
  
• Rickmansworth
  Rickmansworth
  Rickmansworth is a town in the Three Rivers district of Hertfordshire, England, 4¼ miles west of Watford.The town has a population of around 15,000 people and lies on the Grand Union Canal and the River Colne, at the northern end of the Colne Valley regional park.Rickmansworth is a small town in...
  
  
• Watford
  Watford
  Watford is a town and borough in Hertfordshire, England, situated northwest of central London and within the bounds of the M25 motorway. The borough is separated from Greater London to the south by the urbanised parish of Watford Rural in the Three Rivers District.Watford was created as an urban...
  
  
• Garston
  Garston, Hertfordshire
  Garston is a village in Hertfordshire, England, more or less contiguous with Watford and now, despite retaining a local identity, is effectively, a suburb...