Joshua Ihaka pleaded guilty to 26 charges, including possession of firearms and weapons, resisting an emergency worker, theft, failing to answer bail and misconduct in a police jail cell at the Ballarat Magistrates' Court on Tuesday.

Police prosecutor Leading Senior Constable Steve Kent told the court witnesses observed Ihaka driving recklessly before he caused a crash on the Western Freeway in September 2018.

The court heard Ihaka veered left and right, moved into the right lane in a narrow space nearly causing a collision, accelerated rapidly and cut back in front of another vehicle on the Western Freeway near Hopetoun Park.

He then continued to accelerate at an estimated speed of 130km/h to 140km/h until he came up behind a truck while two cars were overtaking in the right hand lane.

Ihaka veered into the left emergency stopping lane to overtake the truck before colliding at a high speed with an empty ute stopped in the lane, pushing it into the traffic and colliding with another car.

The court heard the Western Highway was completely blocked, all three vehicles sustained severe damage and a witness suffered three broken ribs and a fractured sternum.

Continuing a long summary of offences, Leading Senior Constable Steve Kent said Ihaka stole number plates in January and a car in June.

In May police found his car left in Maddingley and discovered a shotgun, seven rounds of ammunition, a handgun, a wooden rifle stock, a knife blade, a folding pen knife, a stanley knife, rifle ammunition and parts that could be used to make shotguns inside.

Also in May police were called to his family's home where he was swinging a baseball bat and damaging property.

The court heard Ihaka filled his car at a petrol station in Bacchus Marsh in July and left without attempting to pay.

In July he was arrested after he was found with a stolen car and stolen number plates.

Leading Senior Constable Steve Kent said in August Ihaka failed to appear at court for previous matters while on bail.

In October police attempted to arrest Ihaka while he was throwing things around his family's backyard, but he pushed the officer and resisted arrest.

After his arrest, he stuck items to the CCTV camera in the police cell and was yelling, kicking and headbutting the cell walls.

A Ballarat defence lawyer said Ihaka was unemployed and living with his parents.

"He had become involved with drugs, had fallen into contact with traffickers and lawlessness where weapons and drugs didn't seem like a big deal," he said.

"He now owns the offending and does not make any excuse and is pleading guilty in some cases at the earliest opportunity."

Ihaka's parents and brother supported him in court and had been visiting him twice a week in prison.

"They have said to me last year they had forgotten what their son was like. Now in remand he has been drug free... his parents have now expressed the son they once knew is back," the defence lawyer said.

The defence lawyer said Ihaka was looking to a 'drug free future' and wanted to work with his brother in construction.

"In my submission, whatever term of imprisonment is required should be followed by a community corrections order that focuses on rehabilitation. That would ensure his ambitions for the future have the best chance of success," he said.

In his sentencing remarks, magistrate Ron Saines said Ihaka's persistent intentions to comply with anything but his legal obligations warranted a lengthy term of imprisonment for deterrence.

"You are heading in your life in such a bad direction you will have nothing but tragedy and disappointment unless you make some changes," he said.

"Of all the offending that driving episode is of grave concern. That is exactly the sort of conduct that leads to the death of other people, if not the death of yourself."

Mr Saines said he took into account Ihaka was a young offender, with parents and a brother to support him.

"If you can reign in your drug use and attraction to criminality you may again win the support of your family," he said.

Ihaka was sentenced to three months in jail. He had already served 47 days in pre-sentence detention.

"The sentence is a lot less than it would have been if you had been 10 years older," Mr Saines said.

"I want you to understand if there is a continuation of your criminality you will be back in prison and may have less family to support you than you have here today.

"You have a month and a half left to serve. That is time for you to plan your release from prison and hopefully see you transition into community without drug abuse, violence and crime."

Ihaka's licence was suspended for two years.

Upon release he will be placed on a 12 month community corrections order with a requirement to complete 150 hours of unpaid community work.