To counteract road crown, manufacturers recommend that the left front wheel be adjusted to have:

To effectively counteract road crown, manufacturers typically recommend that the left front wheel be adjusted to have less positive caster than the right front wheel.

The reason behind this adjustment stems from the design and dynamics of vehicles on crowned roads, where the road surface slopes downward from the center toward the sides. This creates a tendency for the vehicle to drift toward the lower side of the crown, which is usually the right side in countries that drive on the right. By reducing the positive caster on the left front wheel, the steering response and alignment can be better balanced, allowing the vehicle to track more straight and stable despite the inclines.

Having equal positive caster on both sides would not address the asymmetric dynamics caused by the road crown, potentially leading to poor handling and alignment issues. More positive caster on the left could exacerbate the drift toward the right, making the vehicle harder to control in that environment. Therefore, less positive caster on the left front wheel helps create a corrective balance, enhancing stability and control.