Heathcote Road has reopened in both directions following an earlier closure due to excess smoke and poor visibility.
The road had been closed between Macarthur Drive and New Illawarra Road. Diversions have been lifted.
Motorists should allow extra travel time as traffic returns to normal.
Extensive bushfire smoke and dangerous road conditions have forced the closure of Heathcote Road.
A six-day, 2700 hectare hazard reduction burn is underway at Holsworthy Military Barracks, and it has led to smoke spreading across the Illawarra and Greater Sydney.
The burn is on the western side of Heathcote Road, and the route was closed at 6am on Wednesday, September 13 due to excess smoke.
"Heathcote Road is closed in both directions between Holsworthy and Lucas Heights due to very poor visibility caused by smoke in the area," Transport for NSW said.
"The road is closed between Macarthur Drive and New Illawarra Road."
A dangerous driving condition alert for Sydney has been issued by the Bureau of Meteorology.
"Reduced visibility in smoke will make road conditions dangerous during Wednesday morning, mainly about the southern suburbs," the alert said.
"Motorists are advised to take extreme care."
The hazard reduction burn is due to be completed on Thursday, September 14.
Stay up-to-date with fires in your area on the Hazards Near Me app.
Eastbound: Heathcote Rd, M5 Mwy, Davies Rd, Alfords Pint Rd, and New Illawarra Rd
Westbound: New Illawarra Rd, Alfords Point Rd, Davies Rd, M5 Mwy, to Heathcote Rd.
This route is suitable for all vehicles including B-doubles.
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