The government will work to avoid the "disaster" of a hard border between the Northern Ireland and Ireland after Brexit by keeping customs regulation to a minimum, but the RHA said it has reservations about the lack of detail provided.
In a paper on future customs arrangements, the government says the UK "must avoid a return to a hard border, and trade and everyday movements across the land border must be protected".
Avoiding a new customs border, it adds, is key to achieving this, but is subject to negotiations with the EU as the UK prepares to leave it.
Measures set out in the document, which outlines the options of a new, unprecedented customs arrangement with the EU or a "highly streamlined customs approach", are just the first of numerous steps to keep trade across the UK's only land border as "seamless and frictionless as possible".
RHA chief executive Richard Burnett said the association welcomed the aversion to a hard border, as any version of this "would be a disaster".
But he added: "[The report] lacks detail and is vague on how the partnership/arrangement will work so we are awaiting more detail.
"We will certainly hold the government's feet to the fire in future negotiations with the EU over this important principle now they are on the record with this aim."
The government said it will release a document specific to the UK/Ireland land border in due course.
