The truck has a shorter stopping distance.
Work Step by Step
Friction is the force that brings these vehicles to rest. All else being equal, we see from Table 4–2 that the “steel on steel (unlubricated)” coefficient of friction (assuming this applies to the train) is smaller than the “rubber on dry concrete” coefficient of friction (for the truck). The acceleration of the truck is greater, and it will take a shorter time and distance to stop.