More than 7,500 people every day are using Ireland's greatest motoring shortcut – the Dublin Port Tunnel – despite tolls of up
to €12.

The National Roads Authority said more than 16,000 vehicles travel through the tunnel each day, but only 8,500 of them are heavy goods vehicle (HGVs) which can use the road for free. Another 7,500 drivers have proved themselves more than willing to pay the tolls, which range from €12 during peak hours down to €3 at quieter times of the week.

But although it is estimated that close to €400,000 is collected in tolls each week it will still be decades before the €752m cost of constructing the tunnel is paid back.

National Roads Authority spokesman Sean O'Neill said: "The total number of vehicles using the tunnel in 2007 was 3.9 million vehicles with HGVs comprising just over half.

"Total revenue collected in 2007 was approximately €10m and we are currently tracking details for this year."

Operators of the toll road have been consistently surprised by the number of private motorists who have chosen to use the tunnel.

Charges were set deliberately high to discourage high volumes and the possibility of traffic jams.

A source said: "It might have been expected that the numbers paying tolls in the tunnel would be sliding back this year but that certainly doesn't appear to be the case.

"Certainly, the people who are using it feel that time is money and are willing to fork out €12 or €6 or whatever it takes to cut their journey."

Travel times between Dublin Airport and Dublin Port can easily be cut in half at peak times by using the tunnel and a journey that could take an hour can be done in little more than 20 minutes.

The route is thought to be particularly popular amongst staff of the Irish Financial Services Centre, which is just a couple of minutes from the Port's city exit.