The opening of the Dublin port tunnel early next year is expected to bring traffic problems to the M1 as cars and trucks criss-cross three lanes of traffic to get in the right lane.
The problems arise because thousands of heavy goods vehicles (HGV) will have to use overtaking lanes on the M1 when entering or leaving the tunnel at its northern exit, where the M1 will be widened to three lanes.
In addition, lorries exiting the tunnel will have just 1km of the M1 to cross from the fast lanes to access the M50 slip road.
T'he 4.5km tunnel, which at some points is more than 20 metres below the surface, is expected to be completed in December and, after safety checks, will be opened by April 2006. This will coincide with the start of major widening works on the M50, which are expected to last at least five years.
"When approaching the tunnel from the M1, it is the middle and outside lanes which access the tunnel," a spokesperson for Mowlem, the main contractors, confirmed. "The nearside lane will lead to Collins Avenue. When exiting the tunnel, it will be the middle and outside lanes heading northbound on the M1."
As well as negotiating around trucks that are crossing onto the M1's outside lane to access the tunnel, city-bound car drivers travelling down the M1 will have to use the inside lane to avoid entering the tunnel.
Commuters who fail to get into the inside lane in time or who choose to use the tunnel will be charged prohibitively high tolls in an attempt to discourage them from using the tunnel as a "rat run" into the city.
However, Tim Brick, spokes-
man for Dublin Port Tunnel, dismissed suggestions that there will be major problems at the junction. "There will be an extra lane on the M1 to the M50," he said. "Therefore, we don't anticipate any major congestion except during extreme peak times. . . we are happy that all lorries will be accommodated at all times."
Meanwhile there is a question of whether there is a need for such a prohibitive toll, which will be set in September and which will apply only to cars and light commercials.
It has emerged that just 7,000 lorries a day will use the tunnel when it first opens, rising to only 9,000 in three years. When cars and other traffic are included, Dublin City Council predicts that just 30,000 vehicles a day will use the tunnel - well within its 80,000 vehicle capacity. In addition, the council's own surveys reveal a noticeable shift in the number of lorries using Dublin's north port where the tunnel terminates, in favour of the south port.
Traffic management of the tunnel is the responsibility of the city council and the National Roads Authority (NRA). The council is currently devising a heavy goods vehicle traffic strategy, which it says will severely restrict HGV access into the city when the tunnel opens.
Under the strategy it is proposed that lorries with five or more axles be banned from the city between 7am and 7pm unless they have a permit, which will be issued on an "exception rather than the rule" basis. The strategy will mean many more lorries being directed onto the already heavily congested M50.
The strategy will also reveal the council's solution to the problem of the 160 lorries that travel to and from Dublin Port every day, but that are too large to fit into the tunnel.
Although the final strategy document will not be published until the autumn, the draft report shows that major concerns have already been expressed about added congestion on the M50. "Several submissions argued that the implementation of the proposed measures in the strategy is likely to exacerbate problems of congestion on the M50," says the interim report. "One respondent suggested that a strategy should not be implemented until the M50 has been widened and major junctions reconstructed as it is already stretched to capacity."
The port tunnel has faced several problems since construction began including the fact that it cannot accommodate trucks over 4.65m and that it is costing far more than predicted. The project is now some €171 million over budget. In a recent parliamentary debate, the Minister for Transport, Martin Cullen, blamed the cost overrun on several factors.
"I understand from the NRA that the estimated final cost of the tunnel is expected to be €751 million, including price variation, against an estimated cost at tender stage of €580 million," he said. "The increase is mainly due to the price variation clause over the period since tender receipt in 2000, with a limited number of other factors, such as higher than anticipated land settlements, impacting on the cost."