Thousands of Sydney motorists endured a nightmare commute on Wednesday morning, after a peak-hour truck fire of the M5 motorway.

Traffic backed up at least 13 kilometres on the M5, stretching back to the Hume Highway, and 10 kilometres on the M7 after the blaze closed all but one city-bound lane on the motorway at the height of Wednesday’s morning peak.

Police said truck caught fire two kilometres west of the Moorebank turnoff, at Casula, about 7am.

All lanes had been re-opened by 11am. But drivers on the M5, M7, Hume Highway, Camden Valley Way and Campbelltown Road still faced long delays as the backlog cleared.

There are now 2 citybound lanes open on the M5. One lane remains closed as well as the breakdown lane. The fire has been extinguished. The citybound queue is 13km back to Hume Mwy at St Andrews. Southbound traffic on the M7 is queued for 5km. pic.twitter.com/kDaZOD128r

— Live Traffic Sydney (@LiveTrafficSyd) July 30, 2019

The truck driver was not hurt in the fire.

Wednesday’s incident followed similar chaos for city-bound commuters from Sydney’s west on Tuesday.

It came after a truck and a motorbike collided – killing the 22-year-old motorcyclist – on the Church Street off-ramp at Granville. Traffic was queued for nine kilometres on the M4 after all city-bound lanes were closed as a result.

The Sydney Morning Herald said it was the second fatality on the notorious stretch of highway, known as “crash alley”, in just over two months.