A consortium operating speed camera vans recorded operating profits of almost €50,000 per week last year.
The Go Safe consortium secured an €80m Garda Síochána contract in 2009.
The speed vans detect one speeding motorist per hour which works out at 72,000 detections per annum.
The consortium is contracted to provide 6,000 hours per month.
The Go Safe cameras operate on sections of road which have a history of collisions where speed was a contributory factor.
A spokesman for the Xavier McAuliffe led consortium said: "We are cautiously optimistic. While some costs have increased, the financial performance of the company is generally in line with expectation."
He said : "However, as the accounts make clear, we have debts of €10.6 million which will also have to be serviced."
The Minister for Justice Alan Shatter said: "The results of speed surveys carried out in the two years from January 2011 to January, 2013 show there has been a sustained improvement in driver behaviour and increased compliance with the limits in most speed enforcement zones, which is very welcome.