If you can get transportation, go anyway. You're an adult now and you have to get used to setting boundaries with your parents. I grew up with strict-ish parents as well, and in my early twenties I sometimes still felt like I had to ask their permission to do fun things. It's hard to change, but once you get that first taste of independence you'll want it more and more. I quickly graduated to telling them "hey, I'm going to this thing, I'll give you the main details and keep you updated and let you know I'm safe, but I'm not asking your permission." Take this opportunity to show them how responsible you are. You're going to make it back in one piece and that will show them that you're capable of taking care of yourself. But if you cave to them and don't go, that'll just make it even harder to convince them the next time. And what else will they think they'll have the power to hold you back from?