There were long delays on the N4 westbound route out of Dublin this afternoon after gardaí temporarily closed the road at Junction 4 in Newcastle following a traffic accident.
Five fire trucks and an ambulance were among the emergency services at the scene.
The N4 had been gridlocked as far back as the M50 before the road reopened.
Gardaí confirmed a road traffic collision occurred on the N4 outbound at around 2.35pm involving four vehicles.
Two people were taken to hospital with non-life threatening injuries. Investigations are ongoing.
In Cork, the N25 was closed in both directions on the Midleton side of Castlemartyr for several hours as emergency services dealt with a collision involving three vehicles.
It has now reopened to traffic.
The #N4 Westbound at Junction 4 was closed for a time this afternoon.— Dublin Fire Brigade (@DubFireBrigade) August 1, 2020
Firefighter/Paramedics from Tallaght and Dolphin's Barn responded to a four vehicle RTC. No serious injuries sustained.
Take care on the roads this #BankHolidayWeekend. pic.twitter.com/890FwhdrS7
Meanwhile, all rail services, on both the DART and inter-city, were suspended between Connolly Station and Malahide/Howth for a time this afternoon, due to an issue with overhead lines.
Other bank holiday road updates include long delays on the N71 Muckross Rd heading into Killarney, Co Kerry.
There is also very heavy traffic on the N4 northbound through Sligo Town, approaching works at the N16 junction.Nearby, traffic is slow in both directions on the Knappagh Rd/Wine St route (R292).
A report from AA Roadwatch released last week revealed that traffic volumes have doubled in Ireland in the post-lockdown period.
The number of traffic incidents reported by AA Roadwatch has increased by 341% following the easing of travel restrictions.
Since Phase 3, the AA Roadwatch team have reported an average of 53 traffic incidents per week compared to a weekly average of 12 such incidents during lockdown.
The AA has also seen a 20% increase in traffic incidents in Phase 3 compared to Phase 2.
Despite a significant reduction in traffic volumes during the lockdown period, road deaths in 2020 year-to-date are up on last year.
So far this year, 83 people have died on Irish roads, up from 78 at this point last year.