The boffins at Toronto Rehabilitation Institute took an old flight simulator and built a tool to look at footwear and ice. The floor is a layer of ice and the hydraulic support allows it to be tilted to any angle. Most supposed "snow boots" failed at only a few degrees of tilt. Most boots failed at 7° which is the slop of the cutouts in sidewalks to accomodate wheelchairs.
Check out by brand and model at Rate My Treads. I found out about this site from a facebook video that has gone viral so the website is down a lot ( the server is throwing a 503 error).
What did they expect? It's ICE. Studs are the answer.