The reduced speed limit near St. Attracta's secondary school in Tubbercurry is causing problems for motorists.
The straight stretch of road, with a broken white line, now has a 50km limit.
However, according to Clr Jerry Lundy, motorists are unable to see the speed signs as they are too small.
"The signs between St. Attracta's and Tubbercurry town on either side are away too small.
"We are all in favour of safety, but motorists cannot see the signs.
"I'm asking the council if we could increase the size of the signs."
Many motorists were being caught speeding in the area.
Clr Margaret Gormley said that one speed limit should exist along the straight stretch of road.
Clr Pat McGrath added that it was a major concern to the people in the area who were not aware of the speed limit.
The council said that the speed limit signs in question are repeater signs and that they cannot be increased in diameter.
The signs at St. Attracta's are of larger diameter.