Here is a video about blind spots that someone posted a while ago.
https://www.youtube.com/watch?v=lV-rhiGRFTE
Just because you can see a truck doesn't mean it can see you.
If I can't get fully in front of a turning vehicle, and get a good part of the way through the intersection before they turn, then I'll stop behind them. Fortunately most vehicles around here use turn signals, and I look for them.