The system of auto trails was an informal network of marked routes that existed in the United States and Canada in the early part of the 20th century. Marked with colored bands on telephone poles, the trails were intended to help travellers in the early days of the automobile. In the mid-to-late 1920s, the auto trails were essentially replaced in the United States with the system of numbered U.S. Highways. Similar numbering schemes had begun to be implemented in the Canadian provinces as well.