like the other people in this thread, I wouldn't recommend it. It's a cheap and "easy" way sure but there's so many downsides. There's a high chance it won't work and you'll just be left paralyzed or something of the sorts , also it'll likely be incredibly painful. If you want to go out with dignity, you won't get that. other people may be harmed in an accident and bystanders/ the truck driver will be traumatized. Especially if there's no note or anything, they may think of themselves/ get prosecuted as a murderer.