List one type of drive system commonly used in elevators.

The traction drive system is commonly used in elevators due to its efficiency and adaptability for various building heights. This system operates using a series of pulleys and cables, where the elevator car is hoisted by a counterweight attached to the same cable. This design reduces the amount of energy required to lift the elevator car, making it suitable for mid-rise to high-rise buildings.

The traction system provides smooth and adjustable speed control, which enhances passenger comfort. Additionally, its capability to handle heavier loads and its generally lower maintenance costs compared to some other systems make it a popular choice in modern construction.

Understanding the traction drive system is essential for effective elevator operation and design, particularly in urban environments where space and energy efficiency are paramount.