how does the transit run?
The OCC controls vehicle movements by using on-board radio-frequency identification tags installed on tunnel buses and light rail vehicles, their locations tracked by passing over induction loops embedded in the tunnel roadway.
Downtown Seattle Transit Tunnel
 The OCC controls vehicle movements (and formerly operations between buses and trains) by using on-board radio-frequency identification tags installed on tunnel buses and light rail vehicles, their locations tracked by passing over induction loops embedded in the tunnel roadway. 
where is downtown seattle transit tunnel? Seattle, Washington, United States who built it? UNANSWERABLE which are the different stations that the tunnel connects to? Westlake and International District/Chinatown stations does it also connect to any route? Yes, it connect bus routes.
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Downtown Seattle Transit Tunnel [SEP] Operations
The New Flyer buses, dubbed "tunnel buses" by King County Metro, were ordered in 2004 to replace a fleet of Breda dual-mode electric trolleybuses whose overhead wire was to be removed in the tunnel's renovation for light rail; 59 of the dual-mode Breda coaches were converted into fully electric trolleybuses between 2004 and 2007 and moved to surface routes, where they continued to operate for more than a decade before being fully replaced in 2016. The New Flyer low-floor, articulated buses feature a "hush mode" that allowed buses to operate solely on stored electric power within the tunnel, minimizing emissions and noise.