Where is the differential lock typically located on a USN road grader?

The differential lock on a USN road grader is typically located as indicated by the correct answer, which is on the yellow button on the back of the right joystick. This positioning is intentional, as it allows the operator to engage the differential lock with ease and precision while maintaining control of the grader.

Using a button located on the joystick helps the operator quickly activate the differential lock without needing to divert their attention from their primary tasks or take their hands off the controls. Having this feature accessible in such a way can be crucial during operations that require enhanced traction and stability, especially on uneven surfaces or when executing turns.

This design enhances operational efficiency, allowing for smoother navigation and improved handling. The other options listed do not reflect standard configurations on USN road graders, as they would not allow for the level of accessibility and control necessary during grading operations.