Convincing my parents to let me out after dark?

my parents seem to have an irrational fear of the dark, and no ammount of logic can sway their opinion. they wont let me out after dark. im currently 17. iv graduated from high school half a year early. iv never done any form of drugs, or been in trouble with the police in any way what so ever.the problem is, now that im out of school, i work in the mornings at a doughnut shop, then, i show up at my old school at 3:00 to hang out with my friends after school. after an hour and a half walking to my friends house, that leaves me about 45 minutes to hang out, because my parents want me home by 5:30, and it takes 15 minutes to ride my bike home. their excuse is "oh, its getting dark. you could get hit by a car." my bike has a light on the bottom of the seat so traffic can see me, i hav no major roads to cross, its still pretty light out, the sun is just 30 minutes from going down, an even then, theres still glow lighting up the sky. THEN, there are street lights, that seriously light up the road, and side walks really well. i dont see what their problem is. iv tried numerous times to throw some simple logic their way,but they still seem to hold onto this irrational rule of theirs. what can i do to convince them otherwise?