1. to reduce wheel/rail contact stress and abrasion by correcting rail cross-section shape and improving wheel/rail contact relationship;
2. correct/control rail wave mill and low joint. These defects will increase the wheel-rail noise, speed up the deterioration rate of vehicle parts and rail components, and even cause the train speed limit;
3. correction/control of rolling contact fatigue defects. These defects can increase the risk of rail damage and even reduce the effect of ultrasonic rail flaw detection.
4. correction/control of other rail defects (such as wheel rolling, crushing, rail head vertical and longitudinal cracks);
5. Reduce the adverse effects of wheel and bogie movement, which will aggravate the deterioration of rail wear and defects;
6. reduce noise and vibration, reduce the vertical irregularity of common joints and welded joints, control rail wave mill;
7. to mitigate the adverse effects of the large axle heavy wheel, improve the wheel/rail contact conditions;
8. reduce lateral instability of vehicles (hunting movement).