How can pilots determine how much runway is left during landing rollout?

Using runway distance remaining signs is the most effective method for pilots to determine how much runway is left during landing rollout. These signs are strategically placed along the sides of the runway and indicate the exact distance remaining to the end of the runway. This information is critical for pilots to make decisions about stopping the aircraft safely, especially in situations where they may be approaching the runway's end.

While visual inspection of the runway can provide some contextual understanding of the environment, it lacks the precise measurement that the distance remaining signs provide. An altimeter, which measures altitude, is not relevant to determining the length of the runway remaining. Similarly, although aircraft GPS systems can provide useful navigational data, they are not typically used for the specific purpose of measuring runway length during rollout. Therefore, relying on the established signs gives pilots the most accurate and immediate information necessary for safe landing operations.