It could refer to Constituency travel, or to accepting a Minister's invitation to an event outside it, as allowed for under the Act. How are we to know? The Act would allow for both.4. (1) The amount specified in a particular column of the Table to this paragraph is determined as the amount payable to a member of Dáil Éireann as part of the parliamentary standard allowance for the relevant period in respect of travelling facilities for distances, from the member’s normal place of residence in respect of the distance referred to in that column, to and from Leinster House, overnight expenses and travel expenses which the member is obliged to incur in the performance of his or her duties as a member of Dáil Éireann.
The fact that travel to conferences (but not other conference costs) is excluded from the Expenses Allowance, tends to suggest that the TDs are expected to pay the travel out of their Travel Allowance.
The whole thing needs to be clarified.
Most TDs claim the whole allowance, anyway. TDs, right left and centre, can't keep their seats without living an insane whirlwind of a life, tearing around from funeral to match to clinic to the Dail and back.