One of the country's most travelled highways becomes a dual carriageway river as flooding severs the main coastal highway — but there are still roads open. Here's what to know.

According to an update from the site issued on Friday morning, key road closures include:

  • The Pacific Highway in both directions between Coopernook and Purfleet
  • The Oxley Highway between Thrumster and Wauchope, as well as at Rosewood, Long Flat and Mount Seaview
  • Giinagay Way between North Macksville and Nambucca Heads
  • Waterfall Way between Bellingen and Raleigh, and again between Dorrigo Mountain and Thora
  • Failford Road between the Pacific Highway (Maitland Road) and the Newcastle Inner City Bypass
  • Nelson Bay Road between Richardson Road and Williamtown Drive
  • The Illawarra Highway in both directions at Macquarie Pass

Other closed roads in greater Sydney are:

  • Springwood Road at Yarramundi Bridge
  • Cattai Road at Eldon St and Millers Road at Pitt Town
  • Pitt Town Road at McGraths Hill
  • Wakehurst Parkway at Oxford Falls
  • Audley Weir at Royal National Park