Based on land
1. Flat land
These types of roads allow heavy vehicles to maintain approximately the same speed as that of light vehicles.
2. Undulating land
This type of road forces heavy vehicles to reduce their speeds significantly below those of light vehicles.
3. Mountainous land
This type of road forces heavy vehicles to operate at sustained ramp speeds for considerable distances and on frequent occasions.
4. Sheer land
This type of road forces heavy vehicles to operate at lower sustained ramp speeds than those that operate in mountainous terrain, for significant distances and on frequent opportunities.