Northwest Transit Systems Partners (NTSP), a joint venture consisting of STV and Mott MacDonald, will oversee the systems construction of two transformative new light rail extensions that will serve tens of thousands of commuters who will ride future extensions of Sound Transit’s light rail system.

NTSP was approved by the Sound Transit Board of Directors in May. The team will perform systems construction management services for the $3.7 billion East Link Extension, a 14-mile-long extension connecting Seattle, Mercer Island, Bellevue, and Redmond; and the $1.9 billion 4.3-mile Northgate Link Extension between the University of Washington at Husky Stadium, the University District, and the Northgate neighborhood. Both light rail extensions were approved by voters and are key components of a larger system expansion being undertaken by Sound Transit over the next 25 years.

“These two extensions will provide commuters with easier, more reliable access to jobs, schools, retail, and cultural institutions all across Seattle and the surrounding area,” said John Ponzio, STV VP and systems national practice leader. “The end result is a Sound Transit system that aspires to be one of the nation’s best transportation networks.”

Sound Transit estimates that at least 50,000 people a day will use East Link by 2030. Once completed, the extension will be the world’s only passenger light rail service operating over a floating bridge – referring to the section of I-90 over Lake Washington connecting Mercer Island and Seattle.

Trains for the Northgate Extension, which is estimated to serve more than 60,000 weekday riders by 2030 and connect Northgate residents to Sea-Tac Airport in 47 minutes and downtown Seattle in 14 minutes, will operate in twin tunnels from the University of Washington Station.