In mining, a haul road is a purpose-built roadway designed to support the movement of heavy equipment and vehicles, especially haul trucks, used to transport materials such as ore, waste rock, or aggregates from extraction areas to processing plants or other locations within the mine site.
Here are key haul road design standards and guidelines for mining operations based on mining industry best practices and recognized standards:
General design principles
- Haul roads should be designed for safe, efficient truck travel at operating speeds.
- Geometric elements include horizontal and vertical alignment, curve radius, stopping sight distance, and road width.
- Roads should enable drivers to see enough distance ahead to safely stop.
- Curves require super-elevation to reduce centrifugal forces on trucks.
- Gradients generally vary from 0-12% for long hauls, with short hauls possibly up to 20%. Smooth and consistent grades are preferred.
Road width
- For primary haul roads used for two-way traffic, the road width should be at least 3.5 times the width of the largest vehicle regularly using the road.
- Width factors of 2.5x, 3.0x, and 3.5x the design vehicle width are used industry-wide, with 3.5x offering the best safety margin at high speeds.
- Minimum width must accommodate safe passing without collisions, which is critical to avoid incidents.
Safety berms and road edges
- Safety berms should relate to truck tire diameters, generally about 3/4 of tire diameter in height. For large trucks (e.g., 360t), berm height may be about 2.9m.
- Vertical drops over 0.5m at road edges require barriers or other control measures to prevent vehicles or people falling off.
Surface and drainage
- Road crown should be about 2% toward the center for drainage.
- Ditch depth below the sub-base is typically around 0.5m.
- Selection of surfacing (wearing course) materials is important to minimize surface defects and maintain safe driving conditions.
Intersections
- Intersections should be flat and placed away from the top of ramps or sharp curves.
- Sight distances at intersections must be ensured in all directions.
Other considerations
- Sight distance and stopping distance are critical and depend on vehicle braking capacity, road grade, speed, and curve geometry.
- Avoid sharp curves at steep sections or switchbacks.
- Avoid short tangents and varying grades to enhance safety and smooth operation.
These standards derive from formal guidelines such as the USBM (United States Bureau of Mines) design manual by Kaufman and Ault (1977), updated Australian and South African mining road design standards, and regional legislation such as Queensland’s mine road design regulations.
