We all know weekend ski traffic returning to the Denver metro area on I-70 has a tendency for gridlock right around 5 p.m. on Sundays. But the traffic yesterday appeared even worse than usual. At times, it was at a complete halt, giving 9News the opportunity to pull out a microphone and interview drivers. The laments were predictable. It turns out the exceptional slowness was due to the Colorado Department of Transportation stopping traffic for 20 minutes at a time, a practice called metering, because there were so many cars. CDOT wanted to be sure the Eisenhower/Johnson Memorial Tunnel was clear of traffic in case there was an emergency. On Saturday afternoon, I-70's eastbound lanes were shut down and westbound traffic reduced to a single lane in Glenwood Canyon for hours following multiple crashes, reports The Aspen Times. A state trooper was investigating two separate crashes when other vehicles began colliding behind him. In all, 20 vehicles and three semi-tractor trailers were involved, writes The Denver Post.