The number of motorists fined for not paying M50 motorway tolls has dropped by half in the last year.

In the period January to the end of July 2009, almost 900,000 motorists were fined for not paying tolls on time. For the same time period this year, this figure was just 440,000.

Although figures on revenue made through the fines by the National Roads Authority (NRA) are yet to be released, it is estimated by sources within the authority that over €7m has been collected to the end of July of this year.

In the same period last year over €12m was collected in fines.

"Based on [this year's] estimates, it is clear people are complying more and registering beforehand which has resulted in the lesser value of penalties collected," said an NRA spokesman.

Meanwhile, the number of court summonses has risen from the last recorded figure of just over 5,000 to 10,010.

A spokesman for eFlow said: "The court summons process commenced in March 2009. In the period March 2009 to July 2010 a total of 10,010 summonses have been issued. Many of these have been settled out of court."

The number of incorrect penalties issued to drivers also showed a drastic decrease of 70%.

Last November, up to 200 people a day were receiving incorrect fines, and this figure has now fallen to an average of 61 a day.

The system failed to operate correctly in the first week of its introduction for about 20,000 vehicles a day.

The most recently published figures show that the M50 tolling system has brought in revenue of €100m since 2009.

"Significant improvements have been made in the past 12 months," said Simon McBeth, eFlow's director of communications and customer relations. "This reflects the improvements we... have made to our customer service offering, in particular the work of our contact centre and dedicated customer servicing teams."

Figures also show that traffic on the M50 motorway has increased by 1.4 million vehicles in the last 12 months.

"We are seeing an unprecedented number of new customers registering with eFlow, and this has been the case since the first quarter of this year," said McBeth.