The number of people dobbing in dodgy drivers has decreased since cellphone use while driving was banned three years ago.
Last year 252,614 people called the *555 line and in 2011, 247,606 calls were made to the free non-urgent traffic line.
That was down on every other year in the past eight years, with calls to the number peaking in 2005 at 345,307.
Acting national manager for communications centres Superintendent Dave Trappitt said since the ban on cellphone use while driving came into effect in November 2009 the number of calls to *555 had decreased.
The police 2011/12 annual report also noted the decrease in calls to the number since the cellphone ban, and said it had also reduced the volume of incoming non-emergency calls "more than was originally anticipated".
An exception to the rule meant drivers were allowed to make cellphone calls while driving in certain circumstances, and this included making a call to 111 or *555.
But the call was only allowed to be made while driving "if it is unsafe or impracticable for the driver to stop and park to make the call", Mr Trappitt said.
The phone line - which has been in existence for more than 20 years - was a useful tool for police, he said.
"Whilst police don't hold information on the number of prosecutions, warning letters sent or patrol cars dispatched via *555, we do take complaints of dangerous driving very seriously.
"Where possible, we send police units to deal with the risk these drivers pose to other road users or follow up with them afterwards."
This summer the Southern District Police reported an increase in the number of people using the *555 service.
Inspector Andrew Burns said drivers were not "narks" by reporting bad driving, but were helping to keep the community safe.
Police took reports of poor driving seriously, and "we endeavour to take some action".
"Sometimes we can only go so far as telling the person that we have received a complaint, but if we get sufficient information we will prosecute," Mr Burns said.
Numbers of calls to *555 each year:
2012 - 252,614
2011 - 247,606
2010 - 269,761
2009 - 291,992
2008 - 293,013
2007 - 311,518
2006 - 315,703
2005 - 345,307
Number of calls to *555 by month in 2012:
January - 22,086
February - 25,537
March - 22,355
April - 19,618
May - 20,347
June - 19,152
July - 19,227
August - 19,181
September - 18,884
October - 20,721
November - 21,929
December - 23,577