The road starts at the northwest corner of the Warminster bypass, at a roundabout where it meets the A36 and the A350. From here it heads into town along Bath Road. By the Minster the road bears right to run through the winding streets of the town centre. There are a couple of mini-roundabouts en route.
After running through the Market Place the road enters the suburb of Woodcock and leaves town along Boreham Road. On the far side of Boreham it enters open country and follows the valley of the River Wylye. Presently it zigzags over the railway line to end at a roundabout back on the A36.