Techniques are described for using geographic location data of snowplows to update a snow depth associated with a section of a surface street. In one exemplary embodiment, the rail system may be uniquely designed to accommodate perpendicular and angled installations. Fillers including porous, non-pyrogenic silica, and methods of making and using the fillers, are also provided. The orientation of the back rest minimizes risk of spinal compression during use of the machine. Each step or function may be initiated automatically or through user input, and may be used in a single-user, multi-user or collaborative setting. The wave guide channel is filled with a liquid crystal material that is exposed to a light grating to create a variation in an index of refraction of the liquid crystal material in the wave guide channel.