Trucks travelling on sections of Melbourne's Monash Freeway will be restricted to 90 kilometre per hour (kph) speed limits under an 18-month trial to make the road safer.

Key points: Trucks to be slowed between Jacksons and Huntingdale roads

Trucks to be slowed between Jacksons and Huntingdale roads Six-month trial will allow speeds up to 100kph for cars between Ashburton and Toorak

Six-month trial will allow speeds up to 100kph for cars between Ashburton and Toorak Changes may be rolled out on other roads if trial successful, State Government says

Cars will still be able to travel up to 100kph, giving them the chance to move around slower large-haul vehicles.

The restriction for trucks will be in place between Jacksons Road and Huntingdale Road.

A large truck, believed to be carrying loaves of bread, forced the closure of a number of lanes of the Monash Freeway when it caught on fire on Friday.

Sorry, this video has expired Blazing truck closes Monash Freeway

The fire sent a huge plume of smoke into the air over the neighbouring suburbs and motorists experienced lengthy delays.

Roads Minister Luke Donnellan said the trial was aimed at reducing accidents on the Monash.

"If you reduce the number of accidents, on the Monash you'll actually provide a more reliable journey for everybody," he said.

He said it was not about blaming truck drivers.

"Both people are at fault in these instances so you can't say it's only the trucks," he said.

"This is a matter of interaction between the two groups and trying to get a little bit of distance between the two groups."

Mr Donnellan said the second stage of the trial would ban trucks from the freeway's right hand lanes.

Varying speeds on freeway to be trialled

A six-month variable speeds trial will also be in place on the Monash Freeway from early July.

The change will allow motorists to increase their speeds from 80kph to 100kph depending on traffic conditions.

The trial will begin between High Street in Ashburton and Glenferrie Road in Toorak.

Overhead electronic signs, CCTV and road sensors already in place will be used to let motorists know the speed limit.

The Government said if the trial was successful, it would consider rolling out the change to other roads in Melbourne.