A common type of compound machine combines the inclined plane with the wheel and axle, resulting in a slanted series of rolling wheels or bars. These compound machines can be found in grocery store checkout aisles, at airport baggage handling centers and sometimes even on the backs of moving trucks. The wheels make it much easier to slide objects up or down the ramp by minimizing friction, while the inclined plane turns a vertical lift into a gradual rise.
Vehicles designed to transport humans up and down mountains usually involve inclined planes. Some cable cars and ski lifts use motorized wheels on a cable that acts as an inclined plane. Other designs have the car or lift attached to the cable (which still acts as an inclined plane) and run the cable around huge wheels at either end, which act as pulleys. These forms of transportation transfer forward power upward, making the journey slower but easier.
A similar application can be found in the machines that lift wheelchair-bound people to the top of stairways. These devices usually combine a motorized wheel-and-axle set to drive the chair up and down a track that acts as an inclined plane. Not only does the inclined plane conform to the shape of a staircase, it enables a weaker motor to drive the stair lift than would be required to lift the chair straight up, as in an elevator.
Many treadmills can be inclined to simulate walking uphill. In this case, the treadmill combines two wheels that drive the treadmill with an inclined plane that increases the effort required to walk, thus increasing the exercise from a workout. This example differs from the others in that the goal of the incline is to increase effort, not decrease it. In reality, the inclined plane still reduces the effort needed to reach the height at its peak; the added work comes from the unnecessary addition of height.