I have been curious since I drove though Colorado on I70 how bad do the roads have to get before they use those big gates to close them and how often does it happen
It has to be pretty bad. I can remember one specific time that it happened when I was on the road and it impacted me personally, but I think that it happens for certain stretches of I-70 more often, like just west of the Eisenhower Tunnel, for example. Also, there are loads of times that snow chains are required to drive on that stretch of I-70.
This was my personal experience. My husband, our daughter, and I were driving back home after Christmas a few years ago through Kansas, when there was an ice storm and we heard that I-70 had closed down just west of where we were. The roads north to Nebraska and the secondary roads in Nebraska west to Colorado were still open, so we drove north to Nebraska. The roads were covered with sheets of ice that were so slippery that we had to hold onto the SUV to keep from slipping and falling down when we stopped for lunch. The power lines were also coated with the same ice and the wind was making them bounce up and down like sine waves. I didn't see any snap, although I think that some must have, because the first place we stopped didn't have any power.
