MOBILE speed cameras have been switched back on for late-night duty after a month off Victoria's roads.
Private speed camera operator Tenix wound back its operations on July 1 after a string of attacks on operators.
Operators have since been clocking off at 8pm instead of 11pm.
But talks with the State Government and Victoria Police had mobile speed cameras back in action last night with extra security in place.
Police said that there would be video surveillance and patrol cars nearby. An attack in June left an operator covered in glass and suffering cuts and shock.
Assistant Commissioner (traffic) Noel Ashby said drivers who attacked camera operators were cowards.
"There will be police nearby and other forms of evidence collection including video evidence," he said.
Speed cameras generate about $130 million a year for the state.
The number of fixed and mobile speed cameras in Victoria rose from 114 in 2003 to 115 in 2004 and 144 in 2005.