I kind of got annoyed by the low-resolution 64x64 hazard stripe texture, so I did some fiddling and there it is.
It is derived from an existing hazard stripe pattern texture found in tf2 (materials/patterns/harvard_stripe).
That one is 1024x1024 with no vmt file, and is used in the skins on weapons.
This one is downscaled to 256x256, which makes it easy to apply on all things hazardous without having to set texture scale to 0.05 or so.
Comes in 2 versions - with concrete and metal surfaceprop parameters.