This is actually a simple answer, the the system is already in place. There are already thousands of testing centers in the United States (acutally world wide).
Now even when I go to my company's training courses, the test are administered by an outside company. I don't see why college exams could not be also administered by these centers.
Could be a good idea. It means that if a person knew the stuff and could pass the test, a college experience would be superfluous.
I like it!
Our local public library proctors exams given by online schools that require it. There is no charge by the library, either.