What is brake lag?

Question

Because air takes time to flow through the air lines to the brakes, air brakes cannot begin working instantly. There is often a brake lag of at least one-half of a second between the moment the brake pedal is pressed and the moment the brakes begin to work.

Accepted Answer

The time required for the brakes to work after the brake pedal is pressed

Answer

The distance between the brake pedal and the floor

Answer

The amount of air pressure used to stop the vehicle