A man and his father driving down a highway notice a semi-truck obliviously pushing a small white car, which is sideways, down a highway. They try to get the truck driver's attention, shouting, waving, pointing, even hurling insults. Other car drivers seem to notice as well, as a lot of honking can be heard.
Finally the truck gets onto the highway shoulder, but it's not clear whether it stops or not. The most horrifying part of the video, tweeted by @davenewworld_2, isn't the video itself, but the amount of people in the comments that say the same thing has happened to them.