Arterial roads traverse through major forests and are typically permanent two-lane unsealed roads. In some exceptional circumstances, where the road acts as a major thoroughfare, as in Kaingaroa, they may be sealed. Sealing is justified where the additional construction cost is offset by the reduced road and vehicle maintenance cost.
Many smaller forests do not have arterial standard roads. Arterial roads generally:
- Carry more than 80 heavy vehicles per day or greater than 250,000 tonnes per year
- On flat and rolling terrain, have a road width of 9 m, desirable maximum adverse gradient of 8% or 10% for short distances and are designed for speeds of 70 km/hr. Adverse grades are uphill loaded for a truck or vehicle
- On mountainous terrain, have a road width of 8 m, desirable maximum adverse gradient of 10% or 12% for short distances, and are designed for speeds of 50 km/hr.