Route Option One (€3.95bn at 2015 prices): 2.5km viaduct, nine metres above the ground, across Dublin Port, tunnel under Dublin Bay, viaduct across Sandymount strand with a tunnel under Booterstown and tunnel from the N11 to Sandyford interchange.
Route Option Two (€4.2bn): High viaduct across the Port, with a tunnel under bay, across Sandymount Strand, under Booterstown and from the N11 to Sandyford.
Route Option Three (€4.35bn): Cut and cover tunnel across the Port. Tunnel under bay, across Sandymount Strand and under Booterstown and a part tunnel from the N11 to Sandyford.
2008-2011: Statutory procedures, including planning and design stage.
2012: Land purchases.
2013: Contract awarded.
2018: Eastern bypass opens.