You must drive on the right half of the roadway except:

• When you are passing another vehicle
• When you are making a left turn into or from an alley, private road or driveway
• When the right lane is blocked due to obstruction
• All of the above
  Explanation:

  "Use the right half of the roadway unless: 1. You are passing another vehicle. 2. You are making a left turn. 3. The right lane is blocked. Never change lane in the middle of intersection"