Victoria Police figures show rammings have increased from just over 30 in the 2013-14 to 103 in 2015-16. Since July 1 this year, there have been another 51 police cars rammed.

While four police were injured two years ago, 14 were hurt in rammings in the last financial period.

The trend has gone hand-in-hand with the increasing number of drivers going to dangerous lengths to avoid arrest and changes to the pursuit policy.

"There seems to be a change in behaviour over the last couple of years," Deputy Commissioner Andrew Crisp said.

"It seems to be that offenders have become more aware if they drive in an erratic way or in fact ram our vehicles, there's every chance we won't take up a pursuit in relation to that particular person."

"Even before the changes to the pursuit policy, good crooks, good offenders would know if they drove at excessive speed, drove on the wrong side of the road, naturally, we're not going to pursue in that circumstance."

The new figures come after another two police cars were rammed in Melbourne's north.

In one incident, which occurred at 1.50am on Saturday in Preston, there was no apparent reason - such as a pursuit - for the attack.

Two policewomen, both senior constables, were waiting at traffic lights at the High and Wood streets intersection when a grey SUV coming in the other direction drove onto the wrong side of the road and rammed them, hitting the driver's side door.

The car took off. The police officers were uninjured, but shaken.

In the second incident, police had been playing cat-and-mouse with a stolen BMW, again in Preston, for a number of hours on Monday morning.

Police found the car in Macleod about 6am after a passenger tried to steal another car in Springthorpe estate.

The passenger jumped back into the BMW when police approached and the vehicle reversed into the police car, drove forward and hit a gum tree, before reversing into police again and taking off.

Arrests have not yet been made in either case and there were no injuries.

Police Association secretary Ron Iddles called it an alarming trend.

"It's of obvious concern to us that our members are being targeted in this way and it is only by sheer good fortune that our members haven't been more seriously injured to this point," Mr Iddles said. 

The increase has been linked to widespread knowledge among offenders of what they need to do so police won't pursue them, brought about by publicity of the tightening of the pursuit policy last year after several deaths. 

It has put police at odds with their command.

Frustrated beat police call it a "no pursuit policy", but command says it is restricted and officers can continue to pursue as long as they stick to a strict risk assessment, which means chases are called off as soon as dangerous driving begins to occur. 

Police Minister Lisa Neville announced last week the force would be given three new helicopters and an aeroplane so police can monitor fleeing offenders from the air for longer.

Mr Crisp said widespread sharing of knowledge among criminals – who are mostly young men – is the reason behind the rise in rammings.

He said there was a recent case in Bendigo where youth offenders who recently spent time in detention in Melbourne had gone back to the country town and started to engage in the behaviour for the first time.

"It's young people learning from young people about what they can do to try and get away from police and using social media to do that," he said.

"Some of these young offenders are really not concerned about the consequences. They'll continue offending until they're caught."

He said police are catching those responsible.

He said while members have come to expect they could be rammed, it was never a more important time to be a police officer.

"I know it's different out there. I know there's a different style of offending these days and I think and compliment our members for what they do day in and day out," he said.

Anyone with information should phone Crime Stoppers on 1800 333 000 or submit a confidential report.

- The Age