The road measures 6.44 miles long and would take a car obeying speed limits 15 minutes to travel its length.
The A4140 is a A Road and is located in the Zone 4 Highways Region.
This is a true long-distance route, journeying through numerous towns like Bushey Heath, BUSHEY, Stanmore, Harrow, The Hyde, and Preston.
The road connects Hertfordshire and Greater London.