The Difference Between Streets and Roads

In the UK you won't find many roads in the centers of many towns and cities. This isn't because they are pedestrianized. It is because the word 'road' was rarely used as part of a toponym before the late 16th Century. Up until the 17th Century roads were called something else, such as 'streets' or 'lanes'. For this reason any city or town in England, which still retains its medieval street patterns, will probably have very few 'roads' in its center. For example the City of London famously has no roads.

Because of the relative modernity of America as a country I wouldn't expect to see the same lack of streets named 'road' in American cities. However, judging by the maps in The Beautiful Hidden Logic in Cities there appear to be very few roads in lots of American cities as well. Data Stuff has created a series of maps on which city roads are colored to show whether they are called 'Avenue', 'Boulevard', 'Street', 'Road' etc. Most cities in these maps seem to be dominated by streets and avenues.

In the USA I know that lots of cities have organized their grid systems by compass direction. So south-north streets might be mostly called 'streets' while east-west streets are called 'avenues' - or vice versa. However this doesn't explain the lack of roads. This 'compass grid' convention could still be maintained by having 'roads and 'streets' or 'roads' and 'avenues'. Besides in some cities this naming convention isn't used. For example in San Francisco (pictured above) we still have mostly roads called 'streets' and 'avenues' however these are split geographically rather than by compass direction. So in San Francisco we find that streets in the west of the city are mostly called 'Avenue' and roads in the west of the city are mainly called 'Street'.

There must therefore be another reason why cities in the USA don't appear to have many streets named 'Road'. The Wikipedia article on Street argues that "a street is characterized by the degree and quality of street life it facilitates, whereas a road serves primarily as a through passage for road vehicles". According to this definition we would therefore expect to see more 'streets' in busy urban environments and more 'roads' in more rural areas. This rural-urban distinction between 'roads' and 'streets' is new to me (and I'm not sure it is true of UK 'roads' and 'streets') however it may be supported by another map from Data Stuff.

Road Suffixes in the USA contains a number of choropleth maps showing the density of road names in U.S. counties. Data Stuff's analysis of road names suggests that roads named 'road' are by far the biggest number of roads by mileage in the USA - with three times as many roads (by mileage) called 'road' than the next most popular name of roads called 'street'. The lack of streets named 'road' in American cities and the fact that there are more 'roads' than any other form of street in the whole of the U.S. suggests that there is a huge urban-rural split in the location roads named 'road' and 'street'.

Someone needs to carry out a spatial analysis of the distribution of streets named 'road' and 'street' in comparison to population density.