I have an asphalt paved driveway that is low in the gate closed position and high in the open gate position. It is a sixteen foot automatic gate that has developed enough sag over the last two years to begin dragging on the last several inches of pavement before stopping in the open position. It didn't help when the drive was resurfaced and raised the asphalt level somewhat. The gate can not be raised any higher on the post. What I need to know is how I can make a channel in the asphalt where the edge of the gate is hitting. It would only be about three inches in diameter and several inches in length. Can I use a propane torch to soften and mold a shallow trench? I want to make allowance for the gate edge without butchering the driveway, even if it is a relatively small area.