Why do a lot of car drivers have such a problem with Transport trucks passing them, or just being in front of them?

Last night this car was going way under the posted speed limit, when I went to pass it and almost by, it started speeding up keeping me in the passing lane way to long, it finally inched by me, then slowed back down and wouldn’t let me by.
This isn’t the first time, you come up on someone going way under the limit and speed up when you try and pass them, why do they do that?