A judge has fined 32 motorists €448,000 after missing court and ignoring hundreds of unpaid M50 tolls, including a woman whose car had travelled on the motorway 950 times.

The prosecutions included seven commercial vehicle owners among the defendants who did not show up for their Dublin District Court prosecutions.

In their absence, Judge Anthony Halpin imposed fines ranging from €5,000 to €25,000.

Vehicle owners faced five sample charges for dodging the tolls on Ireland's busiest motorway from January to May.

Transport Infrastructure Ireland (TII), the State agency responsible for road and public transport infrastructure, prosecuted them after sending each driver hundreds of warning letters.

Judge Halpin noted the vehicle types and overall records of outstanding charges, and the 32 motorists did not turn up to court despite getting summonses.

In each case he heard evidence of the motorists' level of engagement with the M50 operators and details of vehicle ownership.

He issued a "priority" bench warrant for the arrest of a driver described by prosecutors as "one of the highest offenders".

Seven cases were struck out or withdrawn, and the remaining 23 were adjourned.

The lowest fine was imposed on a private vehicle owner who paid for 56 out of 159 trips.

The driver with the worst record paid for none of the 950 trips, then costing €3.20 each, for her car.

The woman, with an address in Clondalkin, Co Dublin, was fined €25,000.

The court heard motorists received hundreds of warning letters about the charges, and most did not respond to attempts to sort out the payments.

Vehicle owners received lesser penalties when the court heard they paid for some of their charges; a private car owner who paid for 55 out of 376 was fined €7,000, and drivers who each did not pay for any of their more than 100 trips were mainly fined €15,000.

The motorists were also ordered to pay €350 in costs.

Prosecuting counsel Marc Murphy said the cases against 32 defendants could proceed in their absence.

A TII witness confirmed each vehicle's ownership records, the number of passages, and payment history.

Some had recently stopped being owners of the cars subject to the prosecutions.

However, TII had documentation to show they were the owners at the time of the journeys. It also had images of all the vehicles passing the toll gantry.

The court can impose fines of up to €5,000 per charge and a six-month sentence.

However it remains the practice of the motorway authority to pick habitual non-payers to face criminal proceedings.

The standard toll for a private car is now €3.50, which must be paid before 8pm the following day, or there is an added penalty.

The charge ramps up after 56 days. Warning letters and court proceedings follow if it remains unpaid.

Commercial and goods vehicle owners pay higher tolls.

The registered owner is liable in all cases, even if they were not driving.