The minimum engine displacement or cubic centimeter (CC) requirement for motorcycles allowed on highways can vary depending on the country or region. In many countries, there is no specific minimum CC requirement for motorcycles to be ridden on highways. However, there may be certain restrictions or licensing requirements based on the motorcycle's power output or the rider's license class.
For example, in the United States, there is no universal minimum CC requirement for motorcycles on highways. Each state has its own regulations regarding motorcycle engine size and licensing. In general, most states require motorcycles to have a minimum engine displacement of 250cc or above to be eligible for highway use. However, there are exceptions, and some states allow smaller motorcycles on highways as long as they can maintain the minimum speed limits.
It's important to check the specific regulations and requirements of the country, state, or region you are in to determine the minimum CC motorcycle allowed on highways. The Department of Motor Vehicles or the equivalent authority in your area should have accurate and up-to-date information regarding motorcycle licensing and requirements.