Baluarte Bridge saddles in the pylons to form 152 suspenders in a two plane semi-fan layout. The tallest intermediate pier, P9, is high. It crosses a gorge in the Sierra Madre Occidental mountains with a clearance of below the deck, substantially taller than the Eiffel Tower. Its clearance is higher than that of the previous record-holder, France's Millau Viaduct, which has a clearance of . The bridge's central span, long, is also the longest cable-stayed span in North America, longer than that of the John James Audubon Bridge in St. Francisville, Louisiana. Construction on the bridge began on 21 February 2008. The
Kingsmead Viaduct 2005. Improvements to the bridge parapets to bring them up to modern standards were carried out by Hertfordshire Council from July to September 2008. The work included installing 'high containment' parapets above the railway. The bridge spans the Lea Valley, crossing the River Lea, the New River and the A119 road between the Rush Green Interchange near Hertford and the Westmill interchange (north-west of Ware). Also running along the valley floor is the Hertford East Branch Line, which the viaduct crosses between Ware and the Hertford East terminus. Kingsmead Viaduct The Kingsmead Viaduct (or "Kings Meads Viaduct") is a raised