These are a form of franchising which enable local authorities to dictate what bus services are provided in an area and let contracts for the provision of those services.
Math o fasnachfreinio yw'r rhain sy'n galluogi Awdurdodau Lleol i bennu pa wasanaethau bysiau sydd i’w darparu mewn ardal, a rhoi contractau ar gyfer darparu'r gwasanaethau hynny.