Do the UC schools allow you to apply for a single dorm room?

Do colleges (especially the UC schools) allow you to apply for a single room? (i.e. without a roommate)
In a case where the student would prefer to have their room and would be even willing to pay extra for a singles room

Single rooms are rare for freshmen and usually reserved for students with certain medical conditions.

Students who do get single rooms often complain about difficulty in making friends at college.

My son applied for a single room in a UC freshman dorm a couple of years ago and got it. He didn’t find a close group of friends until second year when he had a shared room, but ironically his friends were not his roommates but people he met elsewhere on campus.

It says in today’s paper that UC campuses each admitted hundreds more students for this fall, so I suspect the chance of getting a single has dropped a lot