The route was approximately that of the original A41 road; the Edgware Road, through Watford, Kings Langley, Apsley, the Boxmoor area of Hemel Hempstead, Berkhamsted, Northchurch, Cow Roast and Tring.

3. c. 63), to look after about 26 miles of road between Sparrows Herne near Bushey and Walton near Aylesbury.

It was the turnpike's depot at Sparrows Herne which gave the road its name.

The turnpike survived the coming of the railways until 1872,[1] when it passed to the route's various parishes and highway boards to maintain and the tolls were removed.

Tollkeepers were appointed and paid 10s/6d a week for which they had to man the gate day and night and from which money they had to pay for the oil for the nighttime illumination of the gates with lamps.