Hello Loren, I hope you're having a wonderful day. There's a slight difference between the two grammatically but natively they mean the same thing. If you are taking a test or using it for academic writing then it is best to use 'set up' because this is grammatically proper because of the definition. To set something up is to place or assemble something in position. To put something up is to construct or build something. They may sound the same but are fundamentally different. This is because you don't set up a building you put it up. Meaning you construct it or put it together. Likewise you don't put up a business you set it up. Meaning it is set in a particular place to attract more customers. Hence why it's academically and grammatically correct to use set up instead of put up. So " The police set up roadblocks on all roads" is more correct to use if its for formal use. for informal native use you can use 'set up' or 'put up' because when used natively they are interchangeable but when used formally and grammatically they mean two totally different things. I hope this helps and clarifies the question you were asking.

Both work in this case because to create a roadblock in general you can “set” the obstacles or “set up” the obstacles. It depends on what the obstacles are so without that information you can say both. However, if you state specific types of obstacles, then you may not use “set” if they are objects you don’t place down. For example, let’s say you use nets as the obstacles. In general “set nets” and “puts nets” doesn’t really work so you can only say: the police set up roadblocks with nets. the police put up roadblocks with nets.

This is such a good question Loren! Here other teachers will probably disagree with me, but in my experience the "up" here adds no meaning at all to "put." It can be a phrasal verb (e.g. to put someone up for the night = let them stay with you) but "put up" and "put" in your sentences are synonyms. "Set" = place, whereas "set up" = construct, establish, assemble. So both can be used here, but the meaning is not identical. The issue is that "up" can be added to many verbs without changing the meaning. This is a more casual way of speaking, though. For example, here in Canada, we might say "the sky cleared up after the storm" but this is exactly the same in meaning to "the sky cleared after the storm." Again, some teachers might want to "split hairs" over this one, but don't worry, all your sentences work :)