I recently had a phone interview for job in a different state. Right after the interview, I got an email from the interviewer saying that he'd like to meet me in person and that I should be contacted regarding travel arrangements soon. I responded thanking him for the interview and agreed to traveling to meet him; however, after a week, I still haven't received any travel plans or any other email. This is a large company whose travel department is in a different state.
How should I go about following-up on the travel arrangements? Should I wait longer or recontact the interviewer or something else?
Edit: I feel that this question is different from other questions dealing with what to do when you don't get a response after an interview. In this case, I received a response from the interviewer (suggesting I travel to meet him), and I responded to him. However, there was no follow-up. I don't want to appear over-zealous and impatient to the interviewer, especially if his response could simply be "I already sent the request to the travel department; it just takes time for them to process it."