Donegal County Council engineers say the traffic flow on Pearse Road has improved after new lights were installed at the end of last month.
There have been complaints that the lights have slowed down traffic, and Cllr Michael McBride today called on Letterkenny Municipal District to review the lights.
He was told the suppliers began a validation of the lights yesterday to optimise their phasing, and they have already made some adjustments based on traffic movements.
That process is set to conclude tomorrow, but the lights will be kept under review.