By Diarmaid Fleming
BBC Dublin correspondent
An overturned truck, which took the emergency services six hours to remove, brought large areas of Dublin to a standstill on Monday.
Rush hour is never fun, but many motorists who took to the road in the city ended up having the morning off work - stuck in their cars.
The truck was stranded for about six hours
One of the worst traffic jams the city has ever seen developed after a truck overturned in the city centre at 0550 GMT.
No-one was injured in the accident beside the Point Depot, close to the city's docks and River Liffey.
But the pain was only beginning for hundreds of thousands of people caught up in the ensuing chaos.
It was noon before the police and emergency services cleared the truck from the route: a crane brought to the scene was unfit for the job, and a second one had to be brought in to lift the truck away.
But the chaos led to a huge build-up of traffic, with a jam on the M1 Belfast-Dublin motorway extending as far back as Skerries, 20 miles north of the city.
Motorists stuck for hours drove up the wrong way along the M1 motorway slip road at Donabate, north of Dublin, to escape the misery. It included those rushing to catch flights at the city's airport.
Huge tailbacks remained until the early afternoon, meaning disruption lasting more than seven hours.
The debacle came despite a special garda traffic operation, Freeflow, which is running during the Christmas period.
It is designed to help traffic move quickly through the streets, with extra officers standing sentry on streets and policing bus lanes and roads for illegal parking.
But the Garda were washing their hands of this latest incident, when asked by the BBC for an explanation of what went wrong and why Freeflow turned into something altogether different.
Gardai launched Operation Freeflow in Dublin last month
"This is a press office, we don't do traffic updates," a garda spokesman said.
Queries were referred by the spokesman to Traffic Watch, but a spokeswoman there said she had no information either.
Finding out who is in charge of managing Dublin's chronic traffic was a question which was also asked a year ago.
In November 2006, a lack of co-ordination between police, roads engineers and council officials meant motorists were not warned of spreading gridlock due to work on a water-main in County Wicklow, which brought much of Dublin to a standstill.
Dublin's traffic congestion ranks as among the worst in Europe, with a survey of international cities revealing that congestion was only worse in Calcutta
Although traffic control-centre cameras captured the congestion, warning signs remained blank and no radio alerts were broadcast, leaving motorists unaware of the logjam which lay ahead.
Dublin's orbital M50 motorway became jammed, paralysing much of the city's traffic.
Opposition politicians were scathing at the similar events on Monday, with Fine Gael transport spokesman Fergus O'Dowd saying Dublin needed an emergency traffic plan.
"A single overturned truck at the Point Depot brought gridlock to large areas of the city," he said.
"This incident shows that Dublin traffic is still balanced on a knife edge. It only takes one accident or incident for the whole system to grind to a halt.
"The fact that this happened during Operation Freeflow shows there are still gaping holes in traffic management in the city.
"We urgently need an emergency traffic plan to deal with one-off incidents and to ease year-round congestion."
Dublin's traffic congestion ranks as among the worst in Europe, with a survey of international cities revealing that congestion was only worse in Calcutta.
Inadequate and infrequent public transport means most commuters drive into city centre streets designed in bygone Victorian and Georgian ages.
While Operation Freeflow was launched in a blaze of publicity by garda chiefs in early December, the reality that a city can be choked by one incident may explain the different garda response to Monday's farce.