At the moment, the surface types "mud", "gravel" and "glass" have a "friction" value different from "0.8" (the default value).

This means that map creators should avoid using these surface types in normal maps to prevent players to be annoyed by the slippery surface.

This "fix" adds 3 new surface types: "mudfloor", "gravelfloor" and "glassfloor" to surfaceproperties.txt, inspired by CS:GO in which "glassfloor" was added specifically to prevent this. These new surfaces have normal friction values and come with their unique footstep sounds (mud and gravel) that remained unknown due to the issue. The TF2 team then should update the most common used materials and mappers should use these new surface types instead.

Alternatively, the TF2 Team can instead just update "mud", "gravel" and "glass" to have a 0.8 "friction" value, like in CS:GO where "mud" was updated because it is used in Overpass.