Motorcyclists are being warned to slow down on the Oxley Highway between Mount Seaview and Gingers Creek to keep themselves and essential road workers safe.
Transport for NSW Director North Region Anna Zycki said road crews are installing new guardrails and crash barriers and repairing drainage at various locations along the highway, which is a popular route for motorcycle enthusiasts.
"Work on the guardrail involves installing an extra protection rail below the existing guardrail and is designed to stop bikers involved in a crash from sliding into the steel posts," Ms Zycki said.
"Crash barriers are proven to keep vehicles from crashing down embankments and into trees but their posts can be unforgiving if a motorcyclist loses control and slides into them.
"Unfortunately some riders have been ignoring temporary traffic lights set up to ensure the safety of road users and workers while these upgrades are under way.
"Our road crews have also reported riders speeding up to beat the orange light and speeding close by workers on the road."
Ms Zycki said the installation of the protection rail was initiated following consultation with key motorcycle groups.
"It's disappointing to find some riders are putting in danger the teams who are working hard to provide them with extra protection along this popular route," Ms Zycki said.
"All road users are urged to drive or ride to the conditions, and follow the directions of signs and traffic control at all times."
Work is being carried out from 6.30am to 3.30pm on weekdays, with traffic reduced to one lane during work hours.