Drivers look set to face further road toll hikes early in the new year.

Tolls are already due to increase from this weekend – with fares on routes including the M50 and the M1 increasing from Saturday.

The cost of driving is set to increase further, however, with Transport Infrastructure Ireland (TII) warning it is "highly likely" the rates will go up again in January.

The State agency said an increase in the consumer price index of more than 3% will mean a guaranteed increase in tolls in January.

Speaking at the Oireachtas Transport Committee yesterday, Independent TD Michael Lowry questioned why companies that are making “massive profits” can keep hiking prices.

“Effectively what you are saying is the motorists have to take the hit,” he said.

“The Exchequer has already taken the hit to compensate the controlling companies. I mean how can that be fair or equitable?

“Is the contract so binding? How can it be so lucrative for those companies that everybody takes the extra charges and those companies continue to make massive profits?”

Toll station on the N18 road before Shannon Tunnel, Limerick, County Clare, Ireland

TII Chief Peter Walsh rejected suggestions toll companies are punishing drivers.

“As you rightly refer, costs are going up,” he said. “They are going up for everybody.

“There are 250 people employed in those various toll organisations so costs are rising for them as well.”

From this Saturday, the price of using some of the country's main roads will increase by up to 10%.

Tolls on the M50 will go up by 30c for cars without tags to €3.50, while cars with tags will see a 20c increase.

On the M1, M7, M8, N6, N25 and N18, tolls for cars will rise from €2 to €2.10.