What does it mean when braking distance is extended or shortened?

[McJoy]

Extended braking distance means the distance from when the brakes are applied until the vehicle comes to a complete stop will be longer. Shortened braking distance means the distance from when the brakes are applied until the vehicle comes to a complete stop will be shorter. The length of braking distance is an important factor in determining whether a vehicle's braking system is functioning properly. China's requirements for vehicle braking distance (when unloaded) are: 1. For vehicles with fewer than nine seats: Passenger vehicles with no more than nine seats should have a braking distance not exceeding 19m when the initial speed is 50Km/h. 2. For vehicles with a total mass not exceeding 4.5t: Other vehicles with a total mass not exceeding 4.5t should have a braking distance not exceeding 21m when the initial speed is 50Km/h. 3. For other vehicles: Vehicle combinations should have a braking distance not exceeding 12m when the initial speed is 30Km/h.