How do i get my parents to quit freaking out about me going on a roadtrip with my boyfriend this summer?

me and my boyfriend want to go on a roadtrip this summer between our sophomore and junior years of college. my parents disapprove. greatly. i'm trying to keep their approval because i cant afford to pay for college myself. my parents are concerned that if we go on a roadtrip, it will be nothing but an excuse for us to have sex in several different states. first of all, its none of their business what two consenting adults in a committed relationship do, but i could see why the idea would disturb them. however, i'm planning on waiting til marriage to have sex, and my boyfriend respects this. is there any way to get my parents to see that there is absolutely no reason why i should wait a few more years before going on a fantastic roadtrip, just so that i can get married and not disturb their rules of propriety? how can i get them to consider this logically instead of their brains automatically screaming "that boy will deflower our princess" every time i mention the word roadtrip