Why can't you open/close a convertible top when driving?

Posted by JarJarAwakens@reddit | askcarguys | View on Reddit | 33 comments

I rented a Mazda Miata convertible once and it was the first time I was in a convertible. I tried to open the roof while driving and the computer said you can't open or close the roof at speeds above something like 6 miles per hour. What happens if you are on the expressway and can't safely slow down if it starts raining or hailing?