The Harrow Road is an ancient route in London which runs from Paddington in a northwesterly direction towards Harrow, northwest London. With minor deviations in the 19th and 20th centuries, the route remains otherwise unaltered. There are dozens of other existing roads throughout the United Kingdom using the same name which do not lead to or from Harrow but merely use the name of the town or, in some cases, a person of that name.
More information on the Wikipedia page [1]