Following a recent shift to a new section of road for both directions of traffic travelling between PJ Moodie Memorial Drive and Nile Street, the arrangement is going to get longer.

Transport for NSW says both directions of traffic on the highway between PJ Moodie Memorial Drive and Napoleon Street will be moved onto new road pavement from this Thursday, December 15, completing a one-kilometre traffic switch.

It comes as part of the work to upgrade the Great Western Highway from Kelso to east of Raglan, which will involve new lanes being built to increase the capacity of the road.

Transport for NSW says traffic control and a 40km/h speed limit will be in place from 8am until 4pm this Thursday, which may affect travel times.

It is advising motorists that while work takes place to merge traffic from the existing road onto the new one-kilometre section of the highway, the road surface may be uneven.

To facilitate the upgrade, including drainage work, Nile Street will be closed off at the intersection of Nile Street and Sydney Road from December 15 and residents living in Nile Street will need to exit the street via Christie Street, according to Transport for NSW.

The traffic shifts at Raglan are similar to a traffic change in mid-2016 as the end of the upgrade to the Great Western Highway through Kelso started to loom.

At the time, traffic was diverted onto two new eastbound lanes between Boyd Street and just east of View Street so that westbound lanes could be pulled up.

The upgrade through Kelso ended up being completed in March 2017 and the upgrade from Kelso to Raglan got started about four years later.

Transport for NSW says it is still planning for a December 2023 completion for the Kelso to Raglan works.