Yan Yean Road is closed at Kurrack Road following a serious collision.
Victoria Police is directing traffic away from the incident, onto Kurrak Road towards South Morang.
Eastbound traffic on Gorge Road, South Morang is being directed back towards Plenty Road.
The Department of Transport is asking for drivers to plan ahead and use another route.
Ironbark Road through Diamond Creek, or Plenty Road and Bridge Inn Road through Mernda are good options, according to the department.
Route 901 buses are diverting around the closure and will miss up to 30 stops.
The road will reopen when police have concluded investigations and it is safe to do so, the department said.
