Transport Infrastructure Ireland (TII) summonsed them to appear at Dublin District Court, but they did not show up for their hearings which went ahead in their absence.
Judge Anthony Halpin imposed fines ranging from €5,000 to €20,500.
He remarked: “Honesty is a virtue, but dishonesty is becoming an art form," adding, "we're paying for their tolls".
Every defendant faced five sample counts for unpaid tolls between April and September last year.
However, TII also revealed each motorist's overall track record of unpaid charges.
Judge Halpin noted they did not come to court, the types of vehicles, records of outstanding fares and that most of them made no effort to pay.
The cases involved commercial vehicles: two hauliers and four van drivers who were charged extra.
There were also 11 owners of ordinary private cars, including one man who had 497 unpaid passages but got fined €15,000.
At the time, car owners were expected to pay €3.10 for each trip.
The van owners repeatedly dodged paying €4 per journey while the truckers avoided fares of either €5.30 or €6.40 per trip. A man with a van was given fines totalling €17,000 after the court heard he dodged paying 252 times.
A heavy goods vehicle owner was hit with the most significant fine, €20,500. He had an overall record of 138 unpaid journeys in his lorry.
The judge noted that TII sent hundreds of warning letters to the defendants before bringing the court prosecutions.
Prosecuting counsel Thomas Rice BL (instructed by Pierse Fitzgibbon Solicitors) said the TII obtained certificates detailing the registered owners of the vehicles as well as the images of them passing the toll gantry on the M50 on specific dates.
TII confirmed the details during the hearing, outlining each motorist's number of passages and payment history.
On top of the fines, vehicle owners were ordered to pay €350 in prosecution costs within six months.
The court can impose fines of up to €5,000 per charge and a six-month sentence.
The court has heard that the motorway authority only selected habitual non-payers to face criminal proceedings.
At the time of the offences, the standard M50 toll for a private car was €3.10, which had to be paid before 8pm the following day or face a €3.00 penalty for missing the deadline.
Motorists had 14 days to pay for the journey and the initial penalty or face a further €41 penalty.
After 56 days, there was an additional charge of €103, and if it remained unpaid, the court proceedings followed.
Commercial and goods vehicle owners pay higher tolls.
The registered vehicle owner is liable even if they were not driving.