The study might be oversimplified since large buildings have various strategies to improve wait times. Sometimes there are designated "express" and "local" cars

The study might be oversimplified since large buildings have various strategies to improve wait times. Sometimes there are designated "express" and "local" cars. Sometimes idle cars get pre-positioned at various floors to keep them closer to new calls. Sometimes pre-positioning will be adjusted by time of day, ie assuming most people enter in the morning and leave in the evening. Etc etc.