Which scientific force is primarily responsible for maintaining control of your vehicle?

Inertia

Explanation:

This force ensures that objects remain in one course with less tendency to change direction when in motion or at rest. This force is the reason why you can let free the wheel of a car in motion and the car will more or less maintain course without toppling over. It is this same force that ensures that greater energy is required to launch the car from complete stall to motion.