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Road categories (S1.3)

There are five categories of road, each with a limiting capacity expressed in millions of standard axles (msa) as shown in Table S1.1.
Table S1.1 Road categories

Road category

Traffic capacity

Type 0

Roads carrying over 30 to 125 msa

Type 1

Roads carrying over 10 to 30 msa

Type 2

Roads carrying over 2.5 to 10 msa

Type 3

Roads carrying over 0.5 to 2.5 msa

Type 4

Roads carrying up to 0.5 msa

Roads carrying more than 125 msa are not covered in this Code. Reinstatement designs for such roads must be agreed between the undertaker and the authority.
The road categories in Table S1.1 are based on the expected traffic to be carried over the next 20 years. Each authority must categorise its road network on this basis and the undertaker must use the most current information available from the authority.
Valid traffic flows must be assessed by accurately monitoring commercial vehicles excluding cars and light vans. Traffic growth rates must be determined from the average of at least three separate assessments carried out over at least three years. Where traffic growth rates are expected to increase significantly because of changing traffic patterns, only predictions generated from a recognised planning process may be used. A zero-traffic growth rate must be assumed until accurate information is available.
The reinstatement must be designed using materials specified in A1, A2, A9 and A10. The overall layer thickness must be as specified in A3 to A7 for the various categories of road, footway, footpath, cycle track, verge or unmade ground, and must be compacted to the requirements of S10 and A8.