Within a few months, every mobile speed camera vehicle will be covered in even more highly visible and reflective markings, and mobile speed camera warning signage will include an advisory speed limit on the sign 50 metres out from the truck.

"We don't want your money - we want you to slow down - we want to save your life and the lives of your loved ones," Minister Gay said.

"There's simply no excuse for speeding so we're introducing mobile speed camera cars that cannot be missed.

"Today's landmark changes make what is already the most visible program in the country, even more obvious to motorists.

"There were no pre-warning signs around mobile cameras when I became Roads Minister in 2011 and now, not only do we have three signs in place at each truck, but I've also increased the trucks' visibility and put speed limits on signs to get more people to slow down."

Statistics show speed-related crashes have reduced significantly since mobile speed cameras were introduced.

Mobile speed cameras are an effective deterrent - 99.8 per cent of motorists who pass one do the right thing and do not get fined.

The amount of tickets issued at mobile speed camera locations are reducing which means people are getting the message and slowing down at these high crash locations.

When people do not do the right thing, the NSW government puts all the money from fines back into road safety.

Every cent from fines goes directly into safety initiatives such as flashing lights at schools, high visibility policing including highway patrol cars and motorbike police seen in the CBD, mobile drug testing, education campaigns and road safety engineering work.

Mobile speed cameras are part of the NSW government's overall speeding compliance program that supports NSW Police enforcement to improve road safety.