South Lake Tahoe, CA….UPDATE 1:45pm: SIG ALERT CANCELED. UPDATE 11:15AM: 1PM IS ESTIMATED OPENING TIME OF US50…..Emergency crews are on scene of a traffic accident involving a big rig vs a Dodge Ram at US 50 at Echo Summit. There has been a SIG Alert issued due to extrication and Big Rig involved. All lanes are blocked in both directions. Unknown estimated time of opening. Please be careful out there today as the roads are very slick.