New bridges will be built across the Wilson and Hastings rivers as part of the 23 kilometre Pacific Highway upgrade, being delivered by Lend Lease, between the Oxley Highway and Kundabung.

A Roads and Maritime Service (RMS) spokesperson said work being carried out in January and February included vegetation clearing along the new road alignment, preparation work at the bridge abutments for the Hastings and Wilson River bridges, building drainage systems along the new road alignment and starting earthworks.

The upgrade includes new bridges over the Wilson River at the eastern end of Dalhunty Island and the Hastings River west of Dennis Bridge.

The Wilson River bridge will be 524 metres long and have a navigational clearance of six metres on the southern channel and eight metres on the northern channel.

The new 574 metre-long span over the Hastings River will have a clearance of eight metres.

A spokesperson said work on both bridges would start in February and include piling, building piers, lifting concrete beams into place and completing the bridge deck.

The access channel will be maintained for river craft on both rivers at all times during the building work and marked by navigation buoys.

Speed restrictions will be in place to ensure the safety of river users and workers.

The bridges will be completed in early 2017, weather permitting, allowing the upgraded section of road to be open to traffic later that year.

Work on the Oxley Highway to Kundabung upgrade, which started in October, is part of the larger Oxley Highway to Kempsey upgrade.