In open pit mining, ramps and haul roads are more than just pathways—they are the lifelines that keep ore moving and costs under control. According to Poniewierski (2021), “A good haul road design is one where the operator can drive from the face to the dump with their foot flat to the floor, except for safety speed limits.” Here are some key insights from industry guidelines: 🔹 Gradient Matters – In Australia, a 10% gradient is common for rigid trucks, but in North America, 8% is preferred. Why? Caterpillar data shows that moving from 10% to 8% can double the lifespan of critical components like differentials and wheel groups, reducing costs significantly. 🔹 Width for Safety – For two-way straight sections, aim for at least 3.5× truck width, increasing to 4× truck width on corners. Always add windrows at least half the tyre height for safety. 🔹 Switchback Design – Flat switchbacks are best for mechanical drive trucks, reducing drivetrain stress. If graded, the inside radius should be 2–3% flatter than the main ramp to offset rolling resistance. 🔹 Direction of Travel – Whenever possible, design ramps so loaded trucks travel clockwise upwards with the driver’s cab toward the pit wall—improving visibility and reducing the risk of catastrophic edge failures. 🔹 Drainage & Pavement – In wet or tropical climates, proper drainage and pavement thickness (up to 3 m in poor ground) must be factored into the geometric design to maintain performance. Bottom line: A well-designed haul road saves money, boosts productivity, and—most importantly—keeps people safe. As Thompson (2015) notes, “A safe system acknowledges that humans are fallible… the road system must allow for these errors to minimise hazard.” You can read more here: https://www.deswik.com/whitepapers/guidelines-and-considerations-for-open-pit-designers