Unitary authority
In the United States an Independent city or a consolidated city-county is roughly equivalent to a unitary authority. The city might be separate from any county government, as in Virginia, or merged with a county government, as in San Francisco, California, or as is common in Florida. Another type of local government that is roughly equivalent to a unitary authority is a county when there are no municipal or township governments in the county. That is the case in Arlington County, Virginia, and Baltimore County, Maryland.