I observed Every Mario Kart World Track and audited it. Lower ranks are safer, and higher ranks are more dangerous. The "Safe" Tier is for courses that are almost completely safe and would lead to minor injuries such as scratches or bruises at worst. The "Minor Complications Tier" is for courses that are relatively safe but are more likely to cause injuries due to obstacles or pedestrians. The "Moderate Injuries" Tier is for courses that would likely cause bumps, bruises, concussions, or minor fractures at worst due to more Obstacles, Pedestrians, or large jumps or gaps. The "Broken Bones" Tier is where things start to get serious. Courses with lots of fauna, dangerous obstacles, and unsafe edges are likely to cause crashes, concussions, and Moderate to Heavy fractures at worst but chance of death is low. The "Hospital Now" Tier is for courses that have unsafe pits that may or may not be filled with unknown liquid, large boulders or snowballs, heavy traffic, or heavy obstacles that could cause heavy bleeding, severe fractures, or worse injuries that could hospitalize someone or even cause death in severe cases. The "Death is Likely" Tier is for completely unsafe courses suspended in high areas, filled with literal dinosaurs, or have dangerous obstacles that could kill someone. The final Tier "Many Fatalities" are for absolutely dangerous courses where death lurks around every corner. They may be suspended high in the sky, filled with heavy obstacles looking to destroy anything in their path, or are just straight up filled to the brim with molten lava.