The Millennium Line is SkyTrains middle-aged line and mostly opened in 2002. It has one of the strangest operations of any transit line anywhere where trains originating at VCC-Clark (the end of the extension) pass through Commercial-Broadway's Lower Level run down the entire Millennium Line to Columbia and are then through routed on the Expo Line back through Commercial-Broadway (this time on the Upper Level) over the line they originated on making a full loop and into downtown Vancouver and the Waterfront.
The stations are significantly more modern looking than on the Expo with a large use of glass windscreens and station roofs that are designed to look wooden, almost the entire line runs on an elevated concrete guideway also noticeably more modern with a different emergency pathway design. Mark-II cars were ordered for the expanded rolling stock requirements for the Millennium Line but Mark-I cars are routed onto it interchangeably as well.