A common usage of the phrase is the concept of a ""prima facie" speed limit", which has been used in Australia and the United States. A "prima facie" speed limit is a default speed limit that applies when no other specific speed limit is posted, and may be exceeded by a driver. However, if the driver is detected, and cited by police for exceeding the limit, the onus of proof is on the driver, to show that the speed at which the driver was travelling was safe under the circumstances. In most jurisdictions, this type of speed limit has been replaced by absolute speed limits.