The first 1?3?km Central Link light rail tunnel through Beacon Hill in Seattle was completed on May 8, coming within 5?mm of engineers’ plans. A Japanese-built, laser-guided tunnel boring machine that started work in January 2006 broke through the east side of the hill as a crowd watched. Contractor Obayashi Corp installed more than 800 pre-cast concrete segments that form the tunnel lining. One underground station will be located in the tunnel some 48?8?m below the surface. Construction of the 25?km Central Link light rail line, currently more than 70% complete, began in late 2003, and services should begin between the city centre and Seattle-Tacoma airport in 2009. On April 26, the Sound Transit board of directors approved a programme that will add nearly 80?km of new light rail routes plus a new tram and additional commuter rail and express bus services. The Sound Transit II plan has an estimated cost of $23bn and a completion date of 2027. However, further progress is likely to depend on the outcome of a ballot in November, when voters will be asked to approve raising the sales tax by 0?5% in King, Pierce and Snohomish counties.n

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