The Monash Freeway has been reopened after a serious crash caused traffic chaos.

All citybound lanes were closed for about two hours after a truck collided with another vehicle on Thursday afternoon.

Watch footage of the scene in the video above

Monash Freeway has reopened following a serious crash. Credit: 7NEWS

Cars were made to detour and heavy traffic banked up as emergency crews cleared the scene near Huntingdale Road.

The highway was cleared about 4.30pm but outbound traffic remained slow.

"Traffic remains heavy outbound, with delays pushing back through the Burnley Tunnel and onto the West Gate Freeway," VicTraffic said.

"There's also congestion on several roads around Chadstone, Clayton and Mt Waverley following the detours, which may take some time to ease."

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