King County Metro begins construction on RapidRide I Line, US July 21, 2026 | News, North America News King County Metro Transit (King County Metro) has commenced construction on the RapidRide I Line, which will span 27.4 km in Renton, Kent, and Auburn, Washington, starting in 2027. The RapidRide I Lin... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password