What is the primary feature of the McDonald's drive-thru service?

The primary feature of the McDonald's drive-thru service is quick service without leaving the vehicle. This service model allows customers to place their orders from their cars, receive their food, and continue on their way, all without the need to park or enter the restaurant. The convenience and speed of the drive-thru are designed to cater to customers seeking a fast and efficient food option, making it a popular choice for those on the go.

Indoor dining experience, extended hours of operation, and delivery to home, while beneficial aspects of McDonald's overall service, do not embody the key aspect of what the drive-thru aims to provide. The essence of the drive-thru is about convenience and speed, which is encapsulated in the ability to get food quickly while remaining inside the vehicle.