Police believe today's crash may have been caused by a malfunctioning tow hitch on the truck's trailer.

The semi-trailer was towing a 20-tonne load when the hitch bent and snapped as it turned left at a bend on the Calder Alternative Highway, Leading Senior Constable Peter Dyer believed.

It caused the trailer to come free and roll down an embankment, he said.

Police do not plan to lay any charges in relation to the crash, Leading Senior Constable Peter Dyer said.

A section of the highway between the Calder Freeway and Bendigo-Maldon Road is expected to reopen by evening.

Leading Senior Constable Dyer echoed concerns about safety on the road, after Lockwood resident David Hutchings labelled the stretch "dangerous".

"It's a major thoroughfare for vehicles. Certainly, with the amount of collisions and crashes involving heavy vehicles this is a section we have concerns about," Leading Senior Constable Dyer said.

Update, 2pm

A second truck crash near a recent fatality in Ravenswood underscores the need for action on the Calder Alternative Highway, a Lockwood community representative says.

The road was blocked between the Calder Freeway and Bendigo-Maldon Road as police, firefighters and the SES responded to a crash near Fenton Lane on Monday.

No-one was injured in the latest crash, which occurred three-and-a-half months after a 53-year-old Nyah West man died nearby.

Residents have been campaigning for a safer bypass to help trucks avoid Bendigo for years, Lockwood's David Hutchings said.

"It would go from Ravenswood, past Marong to Leichardt (near Marong)," the community member on the Calder Highway Improvement Committee said.

"This is a major freight route for agricultural products from Mildura and Swan Hill all the way down to the port (in Melbourne). All those trucks have to come down through this little bit of road. It's insane."

Mr Hutchings had been responding to crashes along the stretch of road for 20 years as a member of the CFA.

"It's just dangerous," he said.

Map: Pin denotes area of Monday's crash, not exact location

Many trucks used the Calder Alternate to avoid going into Bendigo, Mr Hutchings said, but modifying the road would be too expensive.

"You can never do anything with this road. It's too windy, too narrow and there are too many trees. You will never make this road better," he said.

Mr Hutchings would like to see a route set down on paper for a new bypass.

"Then when everyone are doing their subdivisions, when councils look at industrial land or we are considering railways, all that stuff, we have that line on the map to plan around," he said.

"Then once we have than line on the map we can start asking for funding."

Update, 12.30pm:

The Calder Alternative Highway is closed between the Calder Freeway and Bendigo-Maldon Road after this morning's crash.

Emergency services are directing traffic.

Crews are on site to recover a truck that lost its trailer and to clear a diesel spill.

VicRoads is urging drivers to consider alternatives to get around the closure, including Lockwood Road and Bendigo-Maldon Road. Allow extra time.

Update, 11.45am:

A southbound lane of the Calder Alternative Highway has been closed after a truck crash at Ravenswood.

The truck involved is sitting on the road and on the verge.

Earlier:

Police are directing traffic on the Calder Alternative Highway after a truck crash on Monday morning.

No one was injured in the crash.

CFA were called to wash diesel from the road.

More to come.

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