A car traveling along the highway needs a certain amount of force exerted on it to stop. More stopping force may be required when the car has:

a higher velocity or more mass??? is this is what you are looking for?

When a car is moving along a highway, it possesses kinetic energy due to its motion. In order to bring the car to a stop, this kinetic energy needs to be dissipated. The rate at which the car's kinetic energy is dissipated and the force required to stop the car depend on several factors.

One crucial factor is the mass of the car. The larger the mass of the car, the more kinetic energy it possesses, and thus more stopping force is required to bring it to a halt. This means that a heavier car would need more stopping force compared to a lighter car when traveling at the same speed.

Another factor is the velocity of the car. The faster the car is moving, the more kinetic energy it has. Consequently, a car traveling at a higher speed would require more stopping force to come to a stop compared to the same car traveling at a lower speed.

Other factors such as road conditions, tire grip, brake efficiency, and air resistance can also influence the amount of stopping force required. For example, if the road is wet or icy, the car may require more stopping force due to decreased traction.

To summarize, a car traveling along the highway would require more stopping force when it has a larger mass, is traveling at a higher speed, or when factors like road conditions affect the car's ability to stop efficiently.