Travel Policy includes sharing rooms!

Our current travel policy requires employees of the same gender to share rooms at company sponsored events. Although the employees dislike this policy very much, it is a cost saving measure implemented from the top down and is part of the company culture. What (if any) is our legal exposure to requiring a policy of this nature? Is this a business conduct norm or do other companies completely eschew the idea?
Comments
I will admit that I work for county government, where we should be careful stewards of the tax payers' dollars, so I don't complain, especially in today's financial environment.
A couple of times, though, I paid for my own room rather than stay with my "partner" and I have driven my own vehicle and did not submit mileage vouchers rather than ride 6 to a vehicle.
Annie