A truck carrying specialist tunnel-boring equipment the Shell refinery project at Bellanaboy has blocked the Glenamoy crossroads in Co Mayo.
The truck got into difficulty while navigating a turn on the narrow roads.
It is understood the lorry was transporting loads of up to 150 tonnes.
A council official said cars can get past the obstruction with care.
Mayo County Council said a first attempt to move the vehicle were unsuccessful.
The Council said it is working with contractors to carry out emergency road widening at the Glenamoy crossroads to provide a temporary solution.
Shell E&P Ireland has apologised for the inconvenience.
Earlier, there were scuffles between protestors and gardaí as the convoy escorting the specialist machinery was blocked on the outskirts of Ballina.
The tunnel boring equipment was being brought from Dublin Port to Erris.