The ring-road around the city been a disaster from start to finish.

It has taken years to complete due to the long drawn-out planning process. There is a serious design flaw in the road because of a decision made in the 1980s, against professional advice, not to build so-called 'clover-leaf junctions'. These junctions . . . the norm internationally . . . allow traffic to move seamlessly from one motorway to the next. However, it was felt that the extra expense of 65m could not be afforded in the depth of recession and, instead, cheaper one-lane slip roads were built at the key interchanges . . . they have become arguably the major source of traffic congestion on the road.

The development of two major shopping centres and other commercial development in close proximity to the M50 has also greatly added to congestion. The road, originally designed to divert traffic from the city centre, has only helped the process whereby the city expanded and sprawled westwards.

And, of course, there was that 1987 deal that allowed NTR build the West Link bridge and charge a toll for driving across it. Given all the other problems with the M50, it would be simplistic to blame the toll gates for all the congestion problems on the motorway. But, as anybody who has inched along in traffic for a mile or two leading up to the toll gates only to face a virtually open road once passing through the barrier can testify, they have certainly been a factor.

Hindsight is, of course, 20-20 and nobody could have predicted back in 1987, when the economy was on the floor and money was literally too tight to mention, that 100,000 cars a day would be using the bridge within two decades.

The word is that, in the early years of the venture, NTR was distinctly nervous about the low numbers using the road.

That said, it is impossible to argue . . . to put it mildly . . .that the 1987 deal was a good one for the country given that the state last week announced it was paying 50m a year, plus inflation, from 2008 to 2020, to buy it out.

Radio shows were, understandably, inundated with angry commuters asking why so much taxpayers' money was being spent on the buyout of the West Link bridge when the tolls were going to continue.

The only consolation for the taxpayer is that, by the middle of next year, barrier-free tolling will be in place . . . which should help ease congestion on the M50.

There have been suggestions in recent days that the government should have bought out NTR's involvement straight away and simply opened up the toll gates until barrier-free tolling could be introduced.

But, aside from the massive loss of revenue to the exchequer from such a move, such is the level of traffic on the road that, without tolling, the supply of vehicles could conceivably increase dramatically and actually lead to a worsening of the problem.

Transport minister Martin Cullen was also at pains to stress last week that barrierfree tolling would only take place at the one existing point along the M50. That is because he got hammered last year when it was suggested there might be a number of toll points along the road. However, one has to question how equitable it is for many motorists to pay nothing to use the M50, while others who have to cross the West Link bridge always have to pay. But this is likely to be a case of realpolitik getting in the way of what is fair.

Aside from barrier-free tolling, the decision in the mid1980s not to build clover-leaf junctions is currently being addressed as part of an expensive 1bn upgrade of the M50.

But the real test as to whether the lessons of the past two decades have been learned comes next month when An Bord Pleanala holds an oral hearing into the proposed Ikea superstore in Ballymun, adjacent to the M50.

No less a body than the National Roads Authority (NRA) has objected to the store, warning that it is likely to result in "significant delays and congestion" on the M50 and "significantly undermine and negate the benefits" of the 1bn upgrade of the motorway.

Green Party TD Eamon Ryan summed up the traffic problems on the M50 when he said a "sweet shop" shouldn't be allowed along it, never mind any major development.