The upgrades to the Sarsfield Road flyover on Cork’s N40 South Ring Road are scheduled to get under way this weekend.
It was one of two new overpasses which opened on the N40 in 2014. However, it has been blighted with water pooling and ponding after heavy downpours.
The issue sparked serious road safety concerns, with Cllr John Buttimer (FG) warning there was potential for aquaplaning on a stretch of road which handles at least 30,000 vehicles a day and where the speed limit is 100km/h.
It is understood that while the flyover was built to required design standards at the time, there had been almost immediate problems with water flow off on its western side.
Last March, engineers conducted a detailed inspection of its drainage system and road surface and identified a number of required improvements.
The works next week will include the resurfacing of a 50m stretch to speed up the flow off of surface water.
Mr Buttimer said it “beggars belief” that a flyover which opened just three years ago, on such an important road, could have been affected by such a problem.
“Transport Infrastructure Ireland needs to review its drainage standards and designs for such roads,” he said.
“But I’m delighted that action is finally being taken to address the issues here. It’s a case of better late than never but we should never have been in this situation.
“This road is already over capacity, with significant queuing on several N40 exits at peak hours and aquaplaning was a severe risk at this location in particular.”
Lane restrictions will be introduced on the N40 between 9pm and 6am this Wednesday and Thursday just west of the Sarsfield Road flyover, to divert westbound traffic via the Bandon Road roundabout.
This localised diversion will then kick in from 9pm on Friday until 6am on Monday to facilitate the upgrade works.
A spokesman for the project said the works will continue around the clock right across the weekend to minimise disruption to traffic.
The traffic lights at the Bandon Road roundabout will be adjusted to cater for the increase in traffic coming from the Sarsfield Road but slight delays are likely during peak times.
Separately, footpath upgrade works which started yesterday on the Sarsfield Road free flow slip lane are due to take about two weeks to complete.