Minnesota does a significant amount of research on road surface materials. There is a section of I94 northwest of the Twin Cities that has three segments of highway, and traffic can be diverted onto one of the segments to test new road surfaces. Here's the MN DOT site with some test videos: http://www.dot.state.mn.us/mnroad/testcells/mainline.html (thrilling stuff).

Now that I'm in MA, I have heard several people say that concrete highways do not last through the winter, despite the large number of concrete-type highways in good condition in MN. Maybe this is the result of careful local road surface research? Roads are certainly better in MN than they are in MA, even though MN has colder and snowier winters. That could just be anti-highway spending sentiment from the big dig though...