This red rope hanging from the garage door opener is not design. It's the emergency release cord of your door. You might not use it for long but when you need it, you'll discover its value. When you pull it down, the opener will be disconnected from the door. What this means is that you'll be able to open the door manually.
It's not called emergency rope without a good reason. It's usually useful during emergencies. It's your solution when the power is out and you still have to get the car out. Modern electric garage door openers have ropes, which can be used from outside too. This way, you can still open the door if you arrive at home and discover that there is power outage. Even though most people today choose to install a backup battery for automatic operation if there is no power in the house, the release cord is still necessary. Actually, it is required by the UL 325 safety regulations.
As a matter of fact, the rope is even more useful during entrapments. What will you do if your child is entrapped under the overhead door and for any reason the reverse mechanism failed to operate? The release mechanism will be your only solution. You will simply disconnect the opener and pull the door up manually. That's the most important reason for having a release rope and also the main reason for its requirement. Since during emergencies you won't have the luxury of time to search for your manual to see how the rope works, it's best to do it now. Most of them work in a similar way but you still have to make sure you know how yours works. During emergencies every second counts!