Comment by bmandale

It is not. Trans people, frequently, look like the opposite sex. Hence there can be no reasonable enforcement of this policy. Cis people, frequently, look like transgender individuals of their own gender. Hence they are liable to receive harassment by any attempt to enforce such a policy. Harassing people, cis and trans, merely trying to use the bathroom in peace, is a far greater imposition than merely existing in the same space as someone else.