WHEN the Northern Cross motorway opens on December 6th it will bring this country one step closer to one of the most radical developments in traffic control this century.

At a total cost of around £70 million, the Northern Cross forms a crucial part of the M50 ring road which, combined with other motorway developments, will eventually allow traffic from Rosslare to travel to Northern Ireland without passing through Dublin city.

It will also link areas as disparate as Tallaght and Malahide, Leopardstown and Howth, cutting driving times by up to 60 per cent. Finally, it opens up new development and industrial possibilities in the suburbs.

The M50 ring road forms a "C" shape around Dublin. Its original intention was to link in all the national primary routes like the spokes of a wheel, so the N1, N2, N3, N4, N7, N81, and N11 all have junctions with it. The Southeastern Motorway will join it at Leopardstown, leading on to the proposed Southern Cross, which eventually joins the Western Parkway - the only section of the ring road currently in operation. This section extends on to the Northern Cross route through Finglas, Ballymun and Coolock.

Construction of the Southern Cross will start early next year, although initial works at Leopardstown Road are due to commence in the middle of this month. The east tie-in is dependent on the route selected for the South-eastern Motorway.

The 11km Northern Cross involves the extension of the motorway from Blanchardstown to Santry, near Dublin Airport. It includes the construction of a dual carriageway at Ballymun Road and North Road, Finglas, and single carriageways at Dun sink Lane, Cappagh Road, North Road, St Margaret's Road, Sillogue Lane, Ballymun Road and Belcamp Lane.

A further extension to the Malahide Road, involving the construction of over three kilometres of 15 metre-wide single carriageway between the Ml at Turnapin and the Malahide Road, is scheduled for completion next August. "That replaces a very substandard road, around 12 feet wide, with a lot of dumping on it," says Fingal County Council's resident engineer on the N11 site, Dermot Hanney. "It will open up that whole area."

Dublin Corporation is working on improving an existing bridge which, combined with the Malahide Road extension, will permit access to Baldoyle, Sutton and Howth via the ring road.

At a national level, the Northern Cross will provide an element of Euroroute €01, linking Rosslare and Dublin Ports, Dublin Airport and Northern Ireland. Fingal County Council is currently awaiting sanction for the stretch of motorway from Dublin Airport to the area known as the Five Roads. When this comes through and the Southern Cross and South-eastern Motorway are complete, there will be an unbroken connection from Rosslare to Northern Ireland bypassing Dublin city entirely.

The Northern Cross has already had an impact on business development along its route. The Woodford Industrial Park, located between Dublin Airport and the Northern Cross with frontage on to Swords Road, is a £12 million, 200,000-square-foot development with Hamilton Osborne King and Sherry Fitzgerald as joint agents. Hella Ireland Ltd, makers of auto-motive lighting and electronic controls, will occupy 30,000 square feet.

According to Paul McNeive, director of the Hamilton Osborne King estate agency, land values trebled within one year of the opening of the Western Parkway and the impending opening of the Northern Cross has seen developers, investors and occupiers directing their attention to the motorway corridor.

"Opportunities on the Northern Cross motorway are far fewer than those which arose on the Western Parkway," says Mr McNeive. "This is mainly because almost all the route of the Northern Cross is through farm lands and land zoned open space, none of which is served by main drainage. Consequently, there are very few industrially-zoned landbanks on the motorway route."

According to Mr McNeive, Fingal County Council is granting planning permission for large industrial/business park schemes serviced by bio-cycle treatment plants and there is now over 500,000 square feet of industrial/business park space under speculative construction along the corridor formed by the motorway.

From the airport side of the Northern Cross, at Turnapin, towards Finglas, the land is mainly agricultural, although there is some land zoned for industry on the Dublin side.

Moving towards Ballymun, there is little zoned land on the northern side, although there are pockets of industry both north and south of the Northern Cross. Much of the land is zoned as open space, however there is a block zoned as residential at Meakstown, near Poppintree, which adjoins the Northern Cross.

From Finglas Road to Blanchardstown, the land is a combination of green belt and agricultural. In fact, most of the land on the northern, non-city side of the Northern Cross is agricultural land; there is, for example, virtually no development north of Charlestown. On the city side of the Northern Cross, there are a lot of infill schemes at Finglas West and there are further development possibilities east and west of the North Road.

On the Northern Motorway, which stretches towards Balbriggan, the land is mainly agricultural with the exception of the Swords area, where there are industrial and green belt areas.

The issue of rezoning has not arisen yet, according to Fingal County Council, since it is still operating under the 1993 development plan which, with the exception of land in Swords, is not due for review until 1999.

HOK has already been involved in the sale of 145 acres of industrially zoned but unserviced land along the motorway route this year, at prices of £20,000-£50,000 per acre.

Meanwhile, the value of smaller prime industrial sites with full services near the airport is about £200,000 per acre.

Mr McNeive also believes the Northern Cross is having a significant impact in attracting multinational companies like Intel, Hewlett Packard and Gateway 2000 to locations near Dublin, since it will provide easy access to Dublin Airport and to large labour pools.

Dublin Airport is a strong selling point. "Proximity to the airport is of huge importance," says James Maher, director of the Sherry FitzGerald estate agency.

"It's also a natural area for people doing business on the north and south to settle in as a distribution centre." Sherry FitzGerald is selling an 11.5-acre site called Northpoint at the Ballymun junction with the Northern Cross, offering direct access to the motorway. About 40 acres to the south of Ballymun junction are also zoned for industrial use, as is some land at Finglas junction.

On the retail side, the motorway will greatly expand the catchment area of the Blanchardstown Town Centre and the newly developed Coolock Retail Park, where 65,000 square feet was pre-let. Planning policy is that any further retail development is to be centred at Blanchardstown, Quarryvale and Tallaght, so it seems that there will he relatively little opportunity for significant new retail schemes along the route.