When are you not required to yield to an approaching emergency vehicle?

• When driving on the opposite side of a multi-lane highway divided with a center median
  Explanation:

  "All vehicles, regardless of the direction of travel, must yield the right of way to an approaching emergency vehicle. This does not apply to vehicles traveling in the opposite direction of the emergency vehicle(s) when traveling on a four-lane limited-access highway with a center median."
• When the emergency vehicle lights are flashing brightly
• When driving on a one-way street
• When the emergency vehicle is directly behind you