Do you think your gf's concerns are based out of her not knowing about cycling and touring? Her view may be set, in which case a rational response won't do any good, but maybe her view can be altered. Have you asked her what her specific concerns and worries are? Would she be as concerned if you were driving? (I imagine not.) What is it about cycling that worries her? Maybe she's just not aware that touring is a common thing that people do. (I just got into cycling last year and before that I didn't really realize people do long trips on bikes. Now I'm really interested in the idea.) Maybe if you could respond to some of her worries by showing her discussion that people have posted on the forum, demonstrating that touring is a well-thought-out activity that really can be done safely, she might come to think of it differently. I'm just saying that maybe if her concerns are taken seriously and responded to on their own merits, maybe then she might come to see that you're approaching the matter in a responsible way. In turn that might allow her to conceive of the activity more open-mindedly, and then she might open up to recognizing how important it is to you to undertake it. Information and anecdotal accounts (both available here on the forums) might be a game changer if she feels like her concerns are really being listened to. Maybe not, but it's worth a try.