All northbound lanes of the Hume Highway were closed on Wednesday afternoon due to a truck crash and fire at Berremangra, northeast of Gundagai and Jugiong.
NSW Transport Management Centre has advised that motorists travelling north are being diverted along Muttama Road, the Olympic Highway and Burley Griffin Way via Cootamundra, Wallendbeen and Harden.
A picture posted to social media by Live Traffic NSW showed that a truck had rolled and caught fire, coming to rest on the centre line between the two northbound lanes at about 2.50pm.
The diversion is suitable for all vehicles and will add approximately 70 kilometres to the northbound journey.
NSW Rural Fire Service posted on Facebook that emergency services were "on scene at a truck fully alight on the Hume Highway at Bookham, in the Yass Valley".
"All Northbound lanes are currently closed and are likely to be for some time," the post stated.
Motorists have been advised to allow extra travel time.
Emergency services and traffic crews are on site.
Live Traffic NSW has warned of "heavy traffic conditions" near the crash site, which was reported to be east of Berremangra Road.
BERREMANGRA: The Hume Hwy is closed Northbound approaching Berremangra Rd due to a truck fire. Use Muttama Rd to Cootamundra, Olympic Hwy to Wallendbeen, Burley Griffin Way through Harden on to Hume Hwy. Suitable for all vehicles pic.twitter.com/5EnEWPtzf9— Live Traffic NSW (@LiveTrafficNSW) June 3, 2020