Bendigo's Mark Wyatt drove past a truck that had lost between 10 to 15 hay bales between Castlemaine and Kyneton during his trip down to Melton on Monday morning just before 8am.

"I reckon one of his straps had got loose," he said.

Ten minutes down the road he saw a mattress come off the back of a trailer and land on the side of the road.

"Heading down there you see it on and off. People just don't have their stuff tied down properly. With the mattress, it was all tarped-up but the wind's just got onto it going up them hills and it was just gone, like that," he said.

"I think it's about people not taking care of their loads."

Mr Wyatt has been driving the freeway six days a week for the past three months for work in Melton and has seen other items fly off the back of utes and trailers including a medium-sized toolbox.

"Even seeing those curtains on the trucks with straps floating loose, because they have not been put down properly. You think 'if something falls off that, it's not going to end very well'.

"You don't know if they know the straps aren't down."

Three years ago, Kyneton police officer Jason Peers went to a call out for five mattresses that had scattered across the freeway.

"Springs under the mattresses were getting caught in cars. You think of a mattress as a soft thing but if a car that is lowish to the ground hits it it can be pretty dangerous," he said.

"So it was absolute chaos. This happened at night too, so people were not seeing the mattresses until they were almost on them."

LSC Peers has seen everything from pallets to cabinets, bedheads and cushions come off vehicles on the Calder.

"A lot of the time they are so smashed up you would not know what they were," he said.

It is often unclear whether the item had not been tied down properly or a rope have snapped.

"You need proper, strong ropes or tie downs. One thing we see is loads moving around under roles, which can make them snap," LSC Peers said.

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Furniture both large and small is among the most common item to come off trailers, along with items from tradies' utes, he said.

"Tie everything down, even if it is heavy or in a trailer cage," LSC Peers said.

"When you are travelling at 110km an hour into a 30 to 50km headwind that wind can be as much as 160km, which is enough to lift just about anything."

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