It really depends on the pregnancy and the length of the trip. If your healthy, no unexpected complications, etc. traveling an hour away wouldn't be a problem. However traveling long distances during the first and last trimester are no reccomended as those are the times when things are most likely to happen.
Talk to your Dr., evaluate the length of your trip and acess to medical facilities if (god forbid) you should happen to need it. Make sure that you have adequate stops so that you are able to move around, that sorta thing.
Safe? Well that really depends on you. As always ask your OB or Midwife what they reccomend for YOUR pregnancy. Best of luck to you!
at 1:27 PM on Nov. 3, 2009