Toll roads have been in existence in Ireland since the 1980s when the East Link first opened. In general toll roads in Ireland impose a toll (levy or charge) on each vehicle using these roads. In recent years, large construction projects have been undertaken and funded by public private partnerships (PPP). This means that a private company provides part of the funding necessary to build the toll road in return for being allowed to toll the road for a set period of time.
All but the M50 work in a normal way, in that you pay your toll at a stop point along the road. The M50 however is a barrier free toll road which is to be paid within 24 hours of passing over the road.