Functional Classes Explained

Functional Class is the hierarchical classification of the road network and is intended to be used to optimise route calculations by routing algorithms.

The Functional Class network must be connected. For each link there must be at least one connection in the network to every other link with the same Functional Class via a link with the same or higher Functional Class. (There are rare exceptions to this rule, such as geometry terminating at a dead end)

Density and pattern of each Functional Class level is influenced by the physical road network that exists in reality. Physical road network density variations between countries and regions within a country are reflected in the Functional Class network.

Functional Class 1, 2, 3, and 4 roads are connected to form a comprehensive road network for navigation of long distance, mid-range and short routes in any given coverage area.

Functional Class levels 1 to 4 must be open to automobiles.

Functional Class Level 1

This is the highest Functional Class level. These roads allow for high volume, maximum speed traffic movement between major metropolitan areas. These roads have very few speed changes. Access to the road is usually controlled.

Functional Class Level 2

These roads allow for high volume, high speed traffic movement between metropolitan areas and major cities. Level 2 roads are used to channel traffic to Functional Class 1 roads for travel between and through cities in the shortest amount of time. Level 2 is published for roads with very few speed changes that allow for high volume, high speed traffic movement.

Functional Class Level 3

These roads allow for high volume traffic movement at a lover level of mobility than Functional Class 2 roads. Level 3 is published for roads that intersect Functional Class Level 2 roads and provide a high volume of traffic movement at a lower level of mobility than Functional Class 2 roads.

Functional Class Level 4

These roads allow for high volume traffic movement at a moderate speed between neighborhoods and cities. These roads connect the Functional Class 5 network to the higher Functional Class network. Level 4 roads connect with higher Functional Class roads to collect and distribute traffic between neighbourhoods.

Functional Class Level 5

These are all of the roads and walkways not classified as Functional Class 1-4. They can also be considered neighborhood or subdivision roads.