The most important component(s) on a vehicle is (in my opinion) the tires. The tires provide vital contact with the ground. This contact enables proper handling, accelerating, and decelerating. While the braking system is important, without tires, the braking system struggles to perform it's duty. If a tire blows out, a vehicle can flip or swerve over into oncoming traffic or off of the road. Tires must be inflated correctly to perform as designed, depending on driving conditions (terrain, vehicle usage, etc.). So while some people may dispute that the braking system is number one considering safety, I think that while still of utmost importance, the braking system is number two on the list. While no vehicle is perfect, a well-maintained vehicle is certainly much safer for the driver, other motorists, and members of the community. Questions/comments are welcome! If you disagree, tell me what you think is most important system/component on a vehicle (for safety)!