Last week, the temperature was turned up.

Trucks banned from the city centre came thundering across the plains of the M50, putting the fear of eternal damnation into your average five eights driver who just wants to get to work in one piece, out of range of shedded loads.

On Monday, there was mayhem. Over 2,000 trucks which normally lumber through the canyons of downtown Dublin, hit out for the circle of hell to join the condemned 100,000 motorists of lesser axels. A breakdown on the Lucan exit added to the sense of doom, with little but Armeggedon up head on the inside lane.

By Thursday morning rush hour, when the Sunday Tribune ventured into the madness, the gridlock had found its own rhythm. We hit the Finglas entry point to the motorway at 7.55am. Things are moving, not fast, but they moving. There is a truck ahead of us. There is a truck behind us. It's as if we are stuck in the middle of a truckin' blues song.

A few minutes later, some chancer speeds by on the hard shoulder. Old M50 hands say one of its eternal curses is the lack of policing that renders it easy meat for chancers. By now, the Blanchardstown exit is in sight. To the right of the motorway, a large sign proclaims that industrial units are for sale or let. Roll up, roll up, let's clog the mother all the way to Rio by throwing a few more sticks on the bonfire of frustrations.

The flashing red light up ahead urges us to drive with care.

The sign also informs us that there are works afoot beyond the toll bridge, just in case we were going to cheer up. And for the comedy angle, the sign flashes that all and sundry should keep speed below 60 km/h for this stretch. We are travelling at 30, and 60 seems like something from a future time.

Then the flashing one tells us that there is a breakdown at J10. J10? The average person doesn't speak in terms of Js on the road. Was that Lucan, or the Mad Cow, or Tallaght, or Palookaville? Fate would keep us guessing.

At 8.22am we reach the queue for Dante's toll bridge. We had travelled 4.1 miles in 27 minutes, which wasn't bad going, according to the penitents who journey daily. The queue is wiped out within a minute. And the woman counting out the loot is as pleasant as these people always are, as if they are attempting to assuage the resentment that is felt for their employer.

Right after the bridge we hit one of the flashpoints, a biblical confluence of vehicles attempting to flow from eight into two lanes, like the rivers of Babylon meeting on a drizzly day. It is here that the prophet Martin Cullen has declared that his will will rule in future years, when the toll is banished forever. Nobody pays too much attention to the Prophet Cullen these days.

On the far side of the bridge, we hit roadworks.

Another sign tells us that five axel trucks are now banned from the city centre. You must be kidding us, Sherlock. For the first time in my life, I find myself counting the axels on passing trucks. The lanes along this stretch are thinner. The trucks loom larger.By now, we are really motoring. The Mad Cow exit flies by at 8.34am. Speeds touch 50mph. Then we come upon it, this morning's Waterloo, the accursed J10. As it turns out J10 is the Ballymount exit, but by now whatever carnage had occurred has been cleared away. A dulcet tone from the AA on the radio tells us we had a lucky escape. A chain reaction from the incident at J10 means that the Naas Road is now chocca. But we sail on, descending now to the low country, the Dublin mountains up ahead on the right, undulating and brown against the morning sky.

The rest of the trip is a doddle, as is the return journey. It would appear that the M50 is as unpredictably unpredictable as the Dublin footballers.

On a good day, it can run like a dream. When the bad days come around, you'd prefer to be on the highway to Basra. Or so they say, anyway.