A SHED fire at the intersection of the Great Western Highway and Jenolan Caves Road has been put out by the Rural Fire Service and Fire and Rescue NSW.

A Colorbond shed near the highway is reported to have gone up in flames before 2pm on Monday.

When crews arrived on the scene, a small grass fire had also started.

The fire was put out just before 3pm.

As of 3.10pm, crews were still on the scene monitoring for flare-ups and spot fires, according to a Rural Fire Service spokesperson.

There was no threat to property at time of publishing.

EARLIER

A BUILDING fire is affecting traffic in both directions on the Great Western Highway.

The incident - at the intersection with Jenolan Caves Road, near Lithgow - is reported to have started at 2.34pm and emergency services and Transport for NSW are on the scene.

Transport for NSW is asking drivers to exercise caution and reduce speed.

Contraflow traffic conditions are reported to be in place to allow motorists to pass in both directions.