SOME weeks ago, when it became known that the Brussels Commission had requested a socioeconomic study to evaluate the respective benefits of the three light rail lines originally "replanned for Dublin, hopes were, raised again on the north side that the Ballymun line would be reinstated. In the context of that examination, it is perhaps worth reminding ourselves of how critical light rail is to the future of the north side.

It is, for instance, useful to remember that the £600 million investment in Dublin's transport system was originally promoted as having a strongly social dimension.

The National Plan promised that the initiatives would "provide better access to job opportunities for areas which currently suffer from high unemployment, extensive social deprivation and low car ownership. They can be expected to contribute substantially to the reintegration of such areas into the mainstream of the commercial life of the city."

Nowhere are these promises more relevant than on the north side. Much of the area which would benefit from light rail falls within what is now being called "North Dublin's Black Arc", a cluster of 33 electoral wards making up the country's largest concentration of people classified as highly deprived.

The population of the Black Arc, at 106,000, is almost as large as Cork City, and is bigger than Galway and Waterford combined. It is a young population with more than half the people under 30.

The Black Arc has

. only 8.7 per cent of the Dublin region's workforce, but 18 per cent of its unemployment.

. an unemployment rate, at 31 per cent, close to double the national average.

. is strongly disadvantaged educationally more than half its labour force left school at or below the age of 15.

Small wonder that the report of the Dublin Transportation Initiative, after several years of wide consultations, recommended a light rail line to Ballymun, with later extensions to Finglas and Dublin Airport. This was warmly welcomed by all of us interested in the regeneration off the north side, as the best stimulus for the area in economic and social terms.

The airport link gave the north side line importance on a national level as well as a local and regional one, because it would provide high quality fast public transport to the airport for the first time. Currently, Dublin must be the only European capital that lacks such a link with its airport.

But in 1994 the need arose to cut budgets, and the aspirations of the National Plan yielded to the narrower considerations of transport economics.

The government at the time decided, on CIE's recommendation, to remove the Ballymun line from the first phase of light rail, and to pursue only the two south side routes as part of that phase. The careful balance of the integrated mix of recommendations from the DTI was inevitably upset by the cuts.

Ironically, the Ballymun line apparently lost out mainly because of "the very deprivation it was intended to address. Since a major transport objective of light rail is to take cars off streets, there is obviously mores scope to do this in affluent Dundrum The evidence as to whether light rail does remove cars from streets is decidedly mixed, but in spite of that, it remains a cardinal principle of the transport rationale.

Another factor that has been mentioned against the Ballymun line is the scale of disruption that would be caused along the Drumcondra Road by carrying out two major infrastructure projects at the same time, namely light rail and the access tunnel to Dublin Port. It is to be hoped that the evaluation study, rather than simply accepting this as an argument, well examine possibilities for passing the construction of two projects 59 as to minimise disruption.

As the Minister, Mr Lowry, said at the launch of light rail last December, experience elsewhere has shown there is considerable scope for reducing disruption through careful planning.

The concern in the north side about the Ballymun line being relegated to Phase 2 is rooted in scepticism that the secondary phase might not materialise. Phase I is being funded with the EU, and it is not unreasonable to speculate that without EU support the project would never have been undertaken.

But Phase 2 can take place only after the year 2000, and it is questionable whether the EU will by then still be in the business of co-funding infrastructural projects of this scale in Ireland.

For this reason, any decision to defer the Ballymun line may in practice turn out to be a decision not to proceed with it at all. It is all to easy to imagine budgetary constraints that, (would prevent any future government from funding such a major project on its own.

The government decision of 1994 was, of course, no more than a provisional decision on routes it has been repeatedly stated that final decisions will be taken only at a later stage of the process. But provisional or not, an unfortunate immediate effect of the 1994 decision was that all preparation and design work stopped on the north side route, while work went ahead on the two south side ones.

It is easy to see how Brussels felt that the ultimate decision was being pre-empted by this approach, since the absence of preparatory work could in itself be an argument against Ballymun.

The light rail project has now become a political football, which is regrettable. I believe there are two things which could be done now to increase public confidence in the present process and restore momentum to this important national project.

First, I suggest that the terms of reference for the consultancy study are published. To avoid further delays in the project, it is important that when the consultants report their conclusion is accepted by all parties.

Second, I suggest that detailed planning be carried out on the Ballymun line, exactly on a par with the preparatory work on the south side routes. If this is not done, it is difficult to see how any decision on routes can be taken on an equal basis.

It is to be hoped that the present process will produce a decision that is not only fair, but is also seen to be fair. After all, the result may well shape the future of Dublin and its people for generations.