at one of my previous employers, we were told to either share a room or pay the cost of a single... at the MANDATORY annual consulting conference (which was held on a WEEKEND!) Fortunately, I ended up rooming with guys I was friends with, but I still see it as an intrusion; the only-once-per-yr part was what kept it from being a breaking point. The other ~ 50 weeks / yr I traveled, I always had my own bedroom. Room sharing was always same-gender unless both persons requested otherwise.

If a project tried to enforce those rules on me now, I'd refuse. I am not sharing a room with a non-family-member when out of town, and I am not tapping my family's monthly budget to pay for a single room when on business travel.