Motorists in Dublin were experiencing severe delays this evening after gardai were earlier forced to close a section of the N4 near Palmerstown after a collision.
AA Roadwatch reported traffic delays of over an hour on several routes in and out of the city including Ballyfermot Road and through Chapelizod village.
South Circular road traffic at Conyngham road was being diverted back into the city and there are major delays on the South Quays. There were also major delays around Heuston Station and St Johns Road West.
Drivers were urgently advised to avoid Ballyfermot, Kilmainham and Islandbridge. They were also warned not to take the Lucan exit off the M50 into the city.
The road was not expected to reopen until later this evening with major problems expected during rush hour.
Elsewhere motorists travelling southbound on the M50 between the N4 and N7 interchanges are being advised to expect delays because of road works.
The two southbound lanes between Coldcut Bridge, south of Lucan, and the Ballymount interchange have been split to facilitate the construction of a central island.
Gardaí have advised that motorists travelling southbound on the M50 can use both lanes but that those wishing to exit at the N7 should use the left lane.
AA Roadwatch reported M50 southbound traffic was still heavy today from the Finglas exit to the Red Cow exit.