What is the final factor that determines if a vehicle will move?

The final factor that determines if a vehicle will move is traction. Traction refers to the grip or friction between the vehicle's tires and the road surface. It is essential for the vehicle to be able to push against the ground in order to generate motion.

Even with an adequately powered engine, a heavy load, or an experienced driver, if traction is insufficient, the vehicle will not move effectively. For example, if the road is slippery due to rain or ice, even a powerful engine may not provide enough grip to start moving or accelerate. Effective traction ensures that the engine's power can be converted into movement, allowing the vehicle to gain forward momentum.

In summary, while engine power, weight of the load, and driver’s skill are all important elements in the operation of a vehicle, it is ultimately the level of traction that determines whether the vehicle can physically move from a standstill.