In the early 19th century, the A151 would have been called a cross-road since it runs across the pattern of these radial routes.
The engineers reasoned that the congestion in the city centre and its radial routes was quickly reaching intolerable levels.
An additional problem is poor interchange with many of the radial routes.
More modern design predominates in the one-off housing on the radial routes.
As the name implies, the line is an orbital circle route linking all radial routes leading to the city.
In subsequent decades, the system developed rapidly, with the opening of radial and tangential routes.
Many of London's major radial routes continue far beyond the city as part of the national motorway and trunk road network.
The line to Wabern became a radial route.
In 1989, state route 77 was commissioned as an additional primary radial route.
He went on to advocate the creation of a system of transcontinental highways with radial routes.