met the border at Hebel but abruptly begun again over east along the border at Mungindi. The Queensland Road Department changed this in 1997 and signed National Route 55 over the border north to St George, and eventually to Charters Towers in later years. With both states' conversion to the newer alphanumeric system between 2005 and 2013, its route number was updated to route A7 between Rolleston and Roma and A55 between Roma and the state border for the highway within Queensland in 2005, and eventually along the remaining highway within New South Wales as route B55 in 2013. Upgrades The Roads of Strategic Importance initiative, last updated in March 2022, includes the following project for Castlereagh Highway. Carnarvon Highway intersection upgrade A project to upgrade the intersection with Carnarvon Highway at a cost of $3.4 million was completed in mid-2022. This project was targeted for "early works" by the Queensland Government. Major junctions See also Highways in Australia List of highways in New South Wales List of highways in Queensland References Highways in New South Wales Highways in Queensland