A state agency says a 24-hour gym, planned for Carrick-on-Shannon, would have a negative impact on the N4.
A decision on the planning application has been paused by Leitrim County Council.
This planning application was lodged in April by AEA Investment Holdings.
It relates to a property on the Dublin Road in Attifinlay, which is the Longford side of Carrick.
A 24-gym would be developed on the ground floor, with accommodation overhead, on the first and second floors.
This includes 26 one and two-bed apartments, for residential use, and 29 one-bedroom suites, for letting.
The site is on the N4, which links Dublin to Sligo.
And, in a submission, Transport Infrastructure Ireland says it's at variance with official policy in relation to development on or affecting national roads.
It says the development would have an adverse impact on the national road.
The council was due to make a decision this month, but they've requested further information.
This includes a traffic and transport assessment to assess the impacts the development would have on the safety and operation of the N4.
A decision on the planning application is on hold until the extra info is received.