I drove the I-80 route last April...ran into snow near Cheyenne. But, the Wyoming Highway Department 511 line plus their placement of live cams along the route, at least make the trip through Wyoming one you can take with good information re: road conditions. I did note that if the weather situation becomes really bad, they shut down the interstate. Take care

 

What provides the added grip in the snow? And you say that you used them in mountain passes instead of chaining up. Did you have any problems convincing anyone that these were good enough? Lastly, how much room do they take up when stored? Looks like a nice thing to carry in the winter along side of the blanket and shovel.