In VFR, what is the purpose of maintaining even or odd thousand foot altitudes?

Maintaining even or odd thousand foot altitudes in VFR (Visual Flight Rules) flight is primarily intended to separate flight operations in opposite directions. This altitude system helps ensure that aircraft flying in a head-on or crossing situation are maintaining safe vertical separation. For instance, aircraft flying at odd altitudes (like 3,000, 5,000 feet) will be designated for flights operating in one direction, while even altitudes (like 2,000, 4,000 feet) are assigned to those operating in the opposite direction. This practice enhances safety by reducing the likelihood of mid-air collisions, as it establishes a systematic way for pilots to maintain vertical separation when flying in congested airspace.