POLICE say they are happy for drivers to flash their lights to warn other motorists about speed cameras.

Traffic Superintendent Dean McWhirter today said he was happy for motorists to flash their lights to warn other motorists they were approaching a speed camera.

"If that occurs I am comfortable with that because it means actually people are getting the message," Supt McWhirter said today.

New speed camera rules explained

Supt McWhirter also defended rule changes, revealed in the Herald Sun today, which allow the hiding of speed cameras behind bushes and road signs.

"It was done to make sure that there was some protection in relation to the mobile speed camera operators," he said.

"To make sure the risk to them is mitigated.

"Unfortunately, what we know is that there have been a number of incidents where mobile speed camera vehicles have been swerved at.

"In the last 12 months there have been 247 incidents of threats in relation to mobile speed camera operators.

"And of those 247 incidents, 110 of those have been swerving at mobile speed cameras."

Supt McWhirter confirmed there would be occasions that operators would be concealed by bushes or signs to protect them.

"That's a commonsense approach," he said.

media_camera Police have changed laws that means mobile speed cameras can be hidden.

The force policy used to say that "under no circumstances" were cameras to be concealed by any covert means.

It also used to ban them on downhill stretches of road unless the site had a significant speed-related crash record.

The new rules - effective immediately - permit mobile speed cameras to be hidden behind trees, bushes, posts and road signs to lessen the risk of harm to camera operators from angry motorists.

They also allow them to be used at the bottom of hills and on slopes if the "road safety objective" can't be achieved at an alternative location.

"There is no restriction from a technical, legislative or enforcement perspective on a mobile road safety camera being operated on a slope, hill or gradient," the new rules say.

The force spent months creating its new policy after the Herald Sun revealed some cameras were being hidden despite the ban and also that fines had to be scrapped because a camera was wrongly set up on a steep hill.

Almost 510,000 motorists paid more than $103 million in mobile speed camera fines in the past year.

media_camera Mobile speed cameras will now be able to be concealed or parked on hills.

Victoria Police yesterday defended the changes to the mobile speed camera policy, saying they included recommendations made by speed camera commissioner Gordon Lewis.

"The amendments were made to specifically focus on the occupational health and safety of mobile speed camera operators, which is paramount in ensuring they can work in a safe environment," force spokesman Leonie Johnson said.

Police told Mr Lewis the use of concealed or partly hidden cameras was necessary to protect camera operators from injury.

Mr Lewis yesterday congratulated Victoria Police for clearly spelling out its mobile speed camera policy in a document that will be publicly available on the camerassavelives.vic.gov.au website.

media_camera Police using mobile radar guns monitor motorists on the Western Ring Road.

"Transparency and clarity are fundamental to the motoring public's trust in the road safety camera system," he said

Police rewrote the rules after Mr Lewis asked Herald Sun readers in October last year to report any mobile speed cameras they believed were being used in breach of force guidelines.

He did so after the Herald Sun revealed speeding fines had to be scrapped because a mobile camera was wrongly set up over the brow of a hill to snap motorists going down a steep slope on Warrigal Rd, Surrey Hills.

Mr Lewis's plea to Herald Sun readers resulted in reports about 116 mobile camera sites they believed breached Victoria Police guidelines.

media_camera An officer targetting speeding drivers.

His nine-month probe found in each case the cameras had been set up fairly and according to the guidelines.

While he did identify three camera sites that were placed on unsuitable downhill stretches of road, he agreed with the decisions of regional police inspectors to override the rules and allow the use of cameras on those hills for safety reasons.

Mr Lewis said it was Herald Sun readers who discovered the controversial hidden camera tactic.

He asked Victoria Police for a ``please explain'' and was told the hidden cameras identified by the readers were put behind shrubs and road signs to protect the camera operators.

Mr Lewis was shown CCTV footage shot from inside a number of camera vehicles showing cars and trucks being driven at camera cars.

Police told him the drivers were ``deliberately intimidating'' the speed camera operators.

keith.moor@news.com.au