CISCO GROVE --
Snow blanketed the Sierra Thursday night causing traffic to back up for about a mile on I-80 near Cisco Grove.
Caltrans said it's the worst jam they've seen this season, and it's because of where drivers pulled over to put their chains on.
"We have a lot of trucks parked too deep on the interstate, so it's brought it to a parking lot," said Dave Wood, Caltrans superintendent for Donner Pass.
Drivers not pulling over far enough and some even stopping in the middle of the road to put on chains caused major problems. Some even dealt with the possibility of being towed because of where they parked.
"It's very frustrating. I don't like this road to sit still, I like it keep it moving, I don't like to see my employees, myself, or CHP on foot," Wood said.
According to Wood there are safer places to get your car ready for the snow.
Checking http://quickmap.dot.ca.gov and paying attention to road signs will show you where chains are needed and how to plan ahead.