The A4 continues along the High Street on its way out of Marlborough via Bridewell Street and Bath Road.
The road passes underneath a covered bridge that links Morris House of Marlborough College to the North Block of the same establishment.
The college is an independent boarding school established in 1843 using some of the buildings that remained after the demise the coaching trade, which saw the original Castle Inn Coaching House close.

The route continues westward through the village of Fyfield, across Overton Hill where there is a parking area at the start of the Ridgeway National Trail and through the village of West Kennet.
On leaving West Kennet there are some parking lay-bys where visitors can walk a short distance from the road to the Neolithic West Kennet Long Barrow, which forms part of the Avebury World Heritage Site.
One mile further along the A4 is Silbury Hill, which is also part of the Avebury World Heritage Site.
A purpose built car park is located beyond the hill on the right travelling westward.

As the route approaches the Beckhampton roundabout, which forms the intersection with the A361, it passes by the Waggon & Horses Inn, built in 1669 to profit from the increasing trade along the old Bath Road.
 It is mentioned in The Pickwick Papers novel by Charles Dickens.

The route continues past Cherhill and the Cherhill White Horse can be seen to the left and nearby the Lansdowne Monument.
The route then descends down the Labour in Vain Hill through the village of Quemerford and into the market town of Calne.

Heading towards the town centre, the road crosses a double mini roundabout, one exit forming the junction with the A3102 to Melksham.
 It follows New Road and passes by the old coaching inn of the Lansdowne Strand.
On the way out of Calne, the road goes along Curzon Street, and then to Chilvester Hill at the roundabout where the northern part of the A3102 splits off towards Lyneham.

The A4 descends steeply before climbing again up Black Dog Hill past the Bowood House Estate.
 The old road used to pass through Derry Hill, but the New Road, as it is called at this point, indicates that the village was bypassed.
There follows a steep descent to the junction with the A342 Devizes road and a sharp right turn past the Lysley Arms towards Chippenham.

On the outskirts of Chippenham is a large roundabout, where the old A4 used to carry straight on down London Road and The Causeway into the Town Centre, which has since been pedestrianised.
Most traffic turns left to go round the Pewsham Estate relief road called Pewsham Way, which is now the classified A4 route.
After four roundabouts, the A4 turns left in a southerly direction at a roundabout, past the Chippenham Magistrates Court.
The route heads downhill over the River Avon on the Avenue La Fleche, named after one of Chippenham's twin towns, to the Bridge Centre roundabout.
The A4 continues along the High Street on its way out of Marlborough via Bridewell Street and Bath Road. The road passes underneath a covered bridge that links Morris House of Marlborough College to the North Block of the same establishment. The college is an independent boarding school established in 1843 using some of the buildings that remained after the demise the coaching trade, which saw the original Castle Inn Coaching House close.
The route continues westward through the village of Fyfield, across Overton Hill where there is a parking area at the start of the Ridgeway National Trail and through the village of West Kennet. On leaving West Kennet there are some parking lay-bys where visitors can walk a short distance from the road to the Neolithic West Kennet Long Barrow, which forms part of the Avebury World Heritage Site. One mile further along the A4 is Silbury Hill, which is also part of the Avebury World Heritage Site. A purpose built car park is located beyond the hill on the right travelling westward.
As the route approaches the Beckhampton roundabout, which forms the intersection with the A361, it passes by the Waggon & Horses Inn, built in 1669 to profit from the increasing trade along the old Bath Road.  It is mentioned in The Pickwick Papers novel by Charles Dickens.
The route continues past Cherhill and the Cherhill White Horse can be seen to the left and nearby the Lansdowne Monument. The route then descends down the Labour in Vain Hill through the village of Quemerford and into the market town of Calne.
Heading towards the town centre, the road crosses a double mini roundabout, one exit forming the junction with the A3102 to Melksham.  It follows New Road and passes by the old coaching inn of the Lansdowne Strand. On the way out of Calne, the road goes along Curzon Street, and then to Chilvester Hill at the roundabout where the northern part of the A3102 splits off towards Lyneham.
The A4 descends steeply before climbing again up Black Dog Hill past the Bowood House Estate.  The old road used to pass through Derry Hill, but the New Road, as it is called at this point, indicates that the village was bypassed. There follows a steep descent to the junction with the A342 Devizes road and a sharp right turn past the Lysley Arms towards Chippenham.
On the outskirts of Chippenham is a large roundabout, where the old A4 used to carry straight on down London Road and The Causeway into the Town Centre, which has since been pedestrianised. Most traffic turns left to go round the Pewsham Estate relief road called Pewsham Way, which is now the classified A4 route. After four roundabouts, the A4 turns left in a southerly direction at a roundabout, past the Chippenham Magistrates Court. The route heads downhill over the River Avon on the Avenue La Fleche, named after one of Chippenham's twin towns, to the Bridge Centre roundabout.
A4 road (England)