Which vehicle has the right of way when meeting on an uphill or downhill slope?

[McLeilani]

On a narrow slope, the vehicle going uphill has the right of way; if the downhill vehicle has already entered the slope while the uphill vehicle hasn't started ascending, the downhill vehicle should proceed first. Advantages of uphill vehicles going first: When both uphill and downhill vehicles are at opposite ends of the slope, allowing the downhill vehicle to proceed first could be extremely dangerous due to its potentially higher speed on the descent. Conversely, if the uphill vehicle goes first, any potential accidents would likely result in less severe consequences compared to downhill vehicles. Example with manual transmission vehicles: When both vehicles meet midway on the slope, for manual transmission cars, making the uphill vehicle yield to the downhill vehicle could easily cause stalling and create dangerous situations like rolling backward on the slope. Moreover, uphill vehicles need to overcome slope resistance by pressing the accelerator harder to generate sufficient engine power and traction. In contrast, downhill vehicles only need to apply brakes temporarily when yielding.