   thumb|right|dublin tunnel construction, 2004 the dublin tunnel (irish: tollÃ¡n bhaile Ãtha cliath) is a road traffic tunnel in dublin, ireland, that forms part of the m50 motorway. the twin tunnels form a two-lane dual carriageway connecting dublin port, which lies to the east of central dublin, and the m1 motorway close to dublin airport. the tunnels are  in length and total project length of . it had final cost of approximately â¬752&nbsp;million. the tunnel was officially opened on 20 december 2006 by then taoiseach bertie ahern; it was initially only open to hgvs.port tunnel to open on 20 december, rtÃ newsport tunnel opens after last-minute delay, rtÃ news it was opened to all traffic on 28 january 2007.port tunnel opens to all users, rtÃ news ==purpose== traffic congestion in central dublin became severe at the turn of the century, with thousands of heavy goods vehicles travelling to and from dublin port via the city centre. the tunnel relieves surface road congestion in dublin city centre by diverting heavy goods vehicles (hgvs) from dublin port directly onto the motorway network. this has positive knock-on effects for bus users, pedestrians and cyclists travelling along the city quays, including better air quality and safer travel. to discourage commuters from using the tunnel, vehicles other than hgvs are heavily tolled. hgvs travelling north and west benefit from the expected six-minute journey time through the tunnel. a tunnel was chosen as it was decided that a surface relief road was not feasible. dublin bus routes 142, 33x and 41x use the tunnel to get to the port area of the
Roads_in_County_Dublin Toll_tunnels Tunnels_completed_in_2006 Tunnels_in_the_Republic_of_Ireland