When flying north or south or are you at odd or even altitudes?

When flying north or south, aircraft typically operate at odd altitudes when heading north and even altitudes when heading south. This altitude assignment helps maintain safe vertical separation between aircraft traveling in opposite directions. For example, an aircraft flying north might cruise at 33,000 feet (odd), while one flying south would be at 32,000 feet (even). This system is part of air traffic control's efforts to ensure safe and efficient airspace management.