How do elevators decide which floor to go to next when lots of people press buttons?

Elevators use scheduling algorithms to manage stops efficiently, balancing wait times and energy usage. The process depends on the type of system in your building:

• Traditional systems: When you press an "up" or "down" button, the elevator control system tracks all pending calls [2]. It generally follows a "cyclic" pattern: a car will continue in its current direction to service all requested floors in that path before changing direction [2]. It makes decisions based on which car is closest, its current direction, and its current load [2].
• "Smart" or destination-dispatch systems: In many modern buildings, you enter your desired floor on a keypad before entering the elevator [1, 3]. The system then calculates the most efficient route and assigns you to a specific car (e.g., Car E or B) [3]. This allows the computer to group passengers going to the same or nearby floors together, avoiding unnecessary stops and preventing elevators from becoming overloaded [1].

Ultimately, the goal of these algorithms is to minimize the total time passengers spend waiting or traveling by ensuring the most logical car handles each request [1, 2].