Sparrows Herne Turnpike Road was an 18th-century English turnpike road from London to Aylesbury. The route was approximately that of the later A41 trunk road, (excluding the modern bypass sections at Watford and Hemel Hempstead), and much of the original route is now numbered as the A4251. It followed the Edgware Road and ran through Watford, Kings Langley, Apsley, the Boxmoor area of Hemel Hempstead, Berkhamsted and Tring. It linked in with other turnpikes to the north forming a route to Birmingham.