How can I convince my mother to let me walk around town at night?

Im 15 and I would like to know how I can convince my mom to let me walk around town at night before the legal curfew. I would much rather love to walk around at night instead of the day, especially since its summer. I've tried to convince her I would be safe; that I would have my cellphone with me at all times, and we live in a smaller town were crimes are virtually nonexistent, but I don't know what else to say. Any ideas on how to convince her?