What size cc can a 14 year old ride in Alabama on the highway?

In Alabama, a 14-year-old can legally ride a motorcycle or moped with an engine size of 50cc or less on public roads, including highways, if they have a valid motorcycle learner’s permit. To operate a motorcycle with a larger engine, they must be at least 15 years old and have obtained a motorcycle endorsement. However, it's essential to check local regulations and ensure compliance with safety requirements, such as wearing a helmet.