As stated in reply to Dáil Reference PQ 200 answered on 8th November last, tolls in Ireland vary according to type and size of vehicles, and reflect inter alia the impact of their use on the toll roads. Toll charges related to vehicle types are publicly available on the www.etoll.ie website.
There is no link between toll charges and motor taxation class. Vehicles of a similar type are all charged the same toll rate regardless of the motor taxation class of the vehicle. The statutory powers to levy tolls on national roads as well as regional and local roads, to make toll bye-laws and to enter into toll agreements with private investors are vested in TII (for national roads) and each local authority (for regional and local roads) under Part V of the Roads Act 1993 (as amended by the Planning and Development Act 2000 and the Roads Act 2007).
There is no basis for rates to correspond between the two very different regimes of 1) tolls for use, and 2) motor taxation.