Answer:
Your vehicle's brakes affects its inertia.
Explanation:
Newton's first law of motion: "An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force." So the build up of inertia can only be affected by the vehicles brakes. If it's an act outside of the vehicle's control the answer may be road or weather conditions.
