Which feature must the driver's side window have?

The driver's side window must roll down to ensure safety and practicality in various driving situations. This feature allows for effective communication with law enforcement officers during stops, as well as the ability to receive emergency assistance if needed. Additionally, being able to roll down the window can be essential for providing fresh air or allowing for easy communication at drive-thru establishments.

Having a window that rolls down promotes a level of flexibility and responsiveness for the driver, enhancing the overall driving experience. Notably, this aspect is part of safety regulations that help ensure drivers can manage unforeseen circumstances effectively.