As a counterpoint, at Caltech during the 70s (at least) it was pretty standard to have a take home final that was (1) no collaboration, (2) closed book, and (3) timed. In fact, I very clearly remember screaming out loud on hard tests as time ticked away. Thank goodness I was in a deserted campus building in the middle of the night. You could study/cram all your notes and texts that you wanted before you put everything away for the test, but, alas, it usually didn't help. They weren't that kind of test.
For non-take home tests of any kind, the campus honor system specifically prevented the professor from staying in the room where the test was being given. They could force the students to collect in one place, but there was a strict rule against any kind of proctoring. The professor or TA with the test passed it out, hung around for a bit to answer any initial questions, and then left the room. They would typically return every fifteen minutes or so to answer any new questions, and then finally return at the time limit to collect the tests. The professor also could not prevent you from taking the test from the specified room and going, say, to the library to take the test. You missed any chance to clarify test questions, and you had to be back before time was up, but they could not force you to stay in a room packed with tense people.
It was pretty refreshing when trust and presumed integrity like that was integrated into the educational system.