However traffic travelling eastbound on the 1930s cliffhugging route still faced speed restrictions at both tunnel locations. For instance the eastbound carriageway at Penmaenbach is subject to a 30 mph (50 km/h) speed limit due to sharp curves and double white lines nominally preclude lane changing. Plans to rectify the awkward alignment by building another tunnel parallel to the current westbound tunnel (as originally intended when the westbound tunnel was proposed) have been discussed for several years. The work in late-2007 at Penmaenbach eastbound has seen the erection of gantries to close lanes when bidirectional working is in place.