GoSafe was paid a flat rate of almost €45,000 a month
The company which operates the country's speed detection cameras was paid €1.2m per month, according to new figures.
The data shows GoSafe received a fee of €151.79 per hour of speed monitoring.
The firm was also paid a flat rate of almost €45,000 a month, while €144.40 was paid for each surveying hour.
The network of 50 GoSafe vans operates at 1,000 locations around the country. It is contracted to provide 7,000 hours of speed monitoring each month.
Several representatives are calling for more clarity.
The Social Democrats want An Garda Síochána to publish full details of any contracts with private companies operating mobile speed detection cameras.
Party co-leader Róisín Shortall said: "It is clearly in the public interest for us to know details of contracts with private companies operating services on behalf of the State’s law enforcement agencies.
"It has been reported that the same consortium has had its contract renewed in 2016 in a deal worth up to €115.5m."
"In the light of this successful Freedom of Information request, the garda and the Department of Justice should now proactively publish details of any current contract with the company, as well as proof of due diligence in the procurement process that led to it reportedly being rewarded a new contract in 2016."
Sinn Féin's justice spokesperson Donnchadh Ó Laoghaire has criticised the costs.
"It is shocking to hear of this level of public funds being spent in such a manner.
"Clearly speed cameras are an important part of managing road safety; they have and do save lives.
"However, elements of this contract are extraordinary, and questions must be asked about the nature of this contract, the levels of expenditure, and whether that represents value for money."
And Fianna Fáil TD Jack Chambers has asked the Public Accounts Committee (PAC) to examine the figures.
Mr Chambers, who is a member of the PAC, said: "This is a vast amount of money and an enormous cost on the exchequer.
"From the very outset, this information should have been publically available and not hidden or shrouded in secrecy.
"It is unacceptable that this information had to be sought through an appeal under the Freedom of Information Act.
"While there can be no doubting the necessity of clamping down on motorists speed on our country’s roads in order to reduce fatalities, failings around the GoSafe speed van prosecutions have been consistently highlighted by judges around the country for some time now."