In my area of suburbia, there are both paved and unpaved alleys. The village over the years has been gradually paving earthen alleys but it’ll take a while to do them all. The village periodically sends a road grader to smooth out the unpaved alleys to eliminate ruts and low spots. A road grader is a road construction vehicle with an earth moving wide blade on the underside.

I saw one plowing an alley the other day in my neighborhood. When the driver is not grading, the two front wheels and the rear wheels are vertical. When grading, the driver tilts the two front wheels at the same angle in the same direction. The rear wheels don’t tilt and always stay vertical.

Just curious to know: It looks bizarre for a truck to have tilted front wheels. What’s the reason for tilting the front wheels? What would happen If he didn’t tilt the front wheels when grading?