From a thread on Sabre Roads (https://www.sabre-roads.org.uk/forum/viewtopic.php?p=1277369&hilit=a582#p1277369) it appears the road may be allocated the A582 road number, quoting a Lancashire county council article (https://www.lancashire.gov.uk/media/939736/notice-of-proposal.pdf). This implies that the current A582 Leyland to Penwortham road may at some future point be re-routed along the current western Penwortham bypass and a trans-Ribble route yet to be built.