Road Hierarchy

A 'road hierarchy' refers to a system of classifying all the roads and streets in a given area, according to their function. Typically this will involve 

  • local access roads
  • distributor roads
  • through roads

Local access roads should be designed to prevent through motor traffic. Through roads should carry long-distance traffic, and the distributor roads connect up the two. 

In the Netherlands this form of classification is necessary under Sustainable Safety, with each authority compelled to classify their road network and implement the appropriate design treatments. This is the principle of monofunctionality.

The City of London has proposed (in 2018) to implement a similar system on their road network, as below.

City of London Road Hierarchy.jpg