The broad questions on travel expectations is good at this stage with hiring manager although I usually don't find them specific on providing policy. The info gathered now helps me formulate questions for a future interview with peers or colleagues who may have similar travel to the role I'm considering. Peers are more likely to tell you details of the policy and how accurately it is followed by the organization (i.e. flexible or what is permitted by policy is actually never approved). If the job requires a lot of travel these sorts of work balance questions are usually broached over lunch with the interviewer assigned to assess culture fit.